Pistachio Sponge Cake

• Using finely grated pistachio will create a more moist texture in the sponge cake. When you finely grate the pistachios, they can distribute more evenly throughout the cake batter, helping to retain moisture and add a subtle nutty flavor. Finely grated pistachios will make your sponge cake a bit more moist compared to using chopped or coarsely ground pistachios.
   
• Baker Note: "When preheating the oven for my cakes, always use the 'top and bottom heat' setting. Please avoid using the fan-forced option, unless otherwise specified." Twenty minutes or longer before baking, set your oven rack in the center of the oven, and preheat the oven to 170°C (338°F).
   
• Grease your wire racks lightly with butter and set them aside; this will prevent the cake from sticking to the wire rack.
   
• Use a small piece of cold butter, and gently rub the cold butter over the bottom and the sides of two 20 cm (8-inch) round baking pans. This technique of using a small piece of cold butter ensures an even, ultra-thin coating. Place a circle of parchment in the bottom of the pan. Add a tablespoon of all-purpose flour and tap it around the inside of the pan until all the buttered surface is covered 100%, then turn the pan upside down over a sink and tap out the excess flour. If you don’t have two pans, it’s okay to bake the cakes in stages; the cake batter will be kept at room temperature until needed.
   
• Bakers Note: All-purpose flour with 8-9% gluten is ideal for tender sponge cake layers; I use 9%. Although 10% works, less gluten is preferable. You can enhance tenderness by mixing in potato starch. Potato starch is my secret ingredient in this vanilla sponge cake. It's very pure and feels silky between the fingers. Do not substitute potato starch for cornstarch. They may look the same and behave similarly, but potato starch is lighter than cornstarch, bakes more thoroughly in cake batter, and yields a softer sponge cake.
   
• Combine 100 grams of all-purpose flour and 50 grams of potato starch (or an additional 50 grams of all-purpose flour instead of potato starch) with 1 teaspoon of baking powder in a medium bowl. Sift the mixture a few times to get the flour as aerated and light as possible.
   
• Bakers Note: When I grate my pistachios, I use the grinder attachment on my ankarsrum mixer to finely grate 150 grams of raw pistachios. If you're using a food processor, take about 50 grams of the sifted flour mixture and process it with the 150 grams of raw pistachios until you have a very fine powder. 
   
• Baker Note: An egg's white-to-yolk ratio can vary. It’s therefore advisable to weigh the egg yolks and egg whites and add or reduce them if needed.
   
• Baker Note: Wipe your mixer bowl with a paper towel dampened with a little lemon juice to eliminate any trace of grease so that the meringue whips up well.
   
• In a clean bowl of a stand mixer fitted with the whisk attachment, put 210 grams of egg whites and a pinch of cream of tartar; whip the meringue on medium speed until it is climbing to the top of the bowl and the meringue is white, glossy, and holds a soft, floppy peak. About 3 minutes. Use a timer!
   
• As soon as the meringue is glossy, add one tablespoon at a time of 200 grams of superfine sugar, and mix on medium-high speed for 3 minutes more to make a very shiny and thick meringue (Use a timer!)
   
• As soon as all of the sugar is incorporated and the meringue is thick, with your mixer on medium speed, add the 140 grams of egg yolks (all at once) and whip for 7 seconds and no longer, or your cake will become flat and dense. Stop the mixer and remove the bowl from the mixer.
   
• Baker Note: Instead of using a large spatula for maximum volume, use a balloon whisk to fold the flour mixture into the cake batter. A spatula will deflate the cake batter more.
   
• Sift one-third of the flour mixture over the whipped meringue/yolk mixture and gently combine with a balloon whisk until well incorporated; repeat this step twice. Use a large silicone spatula at the end of the folding to scrape the side and the bottom of the mixer bowl to make sure all the flour is integrated. Set aside for now while you warm the cream.
   
• In a small saucepan, warm 75 grams of heavy cream and 1 teaspoon of vanilla bean paste over medium heat until warm (about 60 seconds, about 50°C/122°F), then quickly pour the warm cream around the edge of the bowl and gently combine with a balloon whisk or spatula without deflating the batter too much.
   
• Carefully fold in the 150 grams of grated pistachio  in the cake batter in two additions until evenly incorporated. Make sure to check the bottom of the bowl as well; if the grated pistachio is not thoroughly incorporated in the cake batter, the cake will bake unevenly.
   
• Use a scale to weigh the cake batter, then divide the cake batter between the two prepared pans—about 450 grams in each pan. Give your pans just a really good spin on the table; what that does is it takes the cake batter up the side of the pan a little bit, just so that as it's baking, it already has an attachment to kind of move up the side of the pan. So, don't be afraid to really give it a good spin. Get that batter moving up. Don’t tap your baking pans on the kitchen counter to try to get things to level out, especially with this style of cake batter, because banging your pans or dropping them on the table to level the batter actually gets rid of all the air bubbles that you just incorporated into the batter.
   
• Baker Note: Using an oven thermometer will ensure even baking results each time, as every oven is different. Always go with the reading on your oven thermometer rather than the temperature you set on your oven.
   
• Bake both cakes until golden brown, firm on top, and the cake springs back when pressed lightly in the center, about 19 to 22 minutes, depending on your oven and baking pan. Mine was done at 20 minutes. To check if the sponge cake is ready after 18 minutes of baking, you should first look through the oven window rather than open the oven door. If the center appears slightly sunken, give it a minute or two longer while keeping an eye on it. At the 20-minute mark, if the center seems almost set, carefully open the oven and gently press the top of the cake. It should feel firm to the touch and may have a slight bounce to it. This method allows you to monitor the cake's progress without disrupting the baking process.
   
• Then immediately, without delay, run a knife between the sides of the pan and the cake, and invert the cakes immediately onto a wire rack; remove the parchment paper and leave it to cool completely on a wire rack.
   
• Cut both cake layers horizontally to create four even layers., I use a cake leveler; I move the leveler back and forth like a saw; you´ll glide the leveler feet on your work surface to cut your cake.
   
• Keep them covered in plastic wrap until you are ready to assemble your cake.
   
• You can bake the pistachio sponge cake layers up to a month in advance and freeze the cake. After the cake is completely cooled to room temperature, wrap each individual cake with 2 layers of plastic wrap, followed by tin foil, or place it in a ziplock bag. Before using your cake layers, remove the layers from the freezer about an hour before you plan to fill the cake.

Pistachio Paste 
 

• Bakers Note: For this recipe, it's important to use raw unsalted pistachios. I use these green ones with the skins already removed. Do not use salted pistachios, as they will not produce a delicious result. If you can't find pistachios with the skins removed, you can use raw pistachios with skins, but the color and texture might vary slightly.
   
• Bakers Note: Using a high-powered blender, like a Vitamix, or  is essential for achieving a smooth texture. A food processor can also be used, but it might not blend the pistachios as thoroughly, leaving some small bits at the end. While this is still delicious and works for most uses, if you're planing using this pistachio paste to make a pistachio ganache, it's best to use a high-powered blender to ensure everything is dissolved well.
   
• Add 150 grams of raw green pistachios, 100 grams of powdered sugar, 1 tablespoon of vanilla bean paste, a large pinch of sea salt flakes, and 100 grams of heavy cream into a high-powered blender or food processor. A high-powered blender like a Vitamix works best, but a food processor can also be used. Be carefull to not over heat the blender.
   
• Blend the mixture until it becomes finely blended and starts forming a very smooth paste. This process can take about 10 minutes. Stop occasionally to scrape down the sides and bottom of the blender or food processor to ensure even blending. Continue blending until the pistachio paste is very smooth. Use immediately to make the pistachio ganache, in the next step.
   
• Baker's Note: Sometimes it’s difficult to scrape the pistachio paste out of a blender. To make this easier, you can warm 500 grams of cream, as mentioned in the pistachio ganache recipe below, to about 60°C (140°F). Pour this warm cream over the pistachio paste in your blender and blend on low speed until combined. This method helps dissolve any small pieces of pistachio paste that might be left. Do not use cold cream, as it could turn into whipped pistachio cream. Additionally, do not let the cream boil, as this can prevent it from whipping up later on. After blending, pour the mixture into the saucepan to warm it to the right temperatur and proceed with the recipe as described.

Pistachio Ganache

• The unwhipped Pistachio Ganache must chill in the fridge for at least 6 hours, preferably overnight, before whipping it into a fluffy pistachio cloud. So plan ahead when making this ganache. 
   
• Baker's Note: To get that dreamy, airy texture in your ganache, use a high-quality white chocolate, such as one with 28 to 32% cocoa butter content. Something like Callebaut Velvet 32% is a solid pick for melt-in-your-mouth perfection as this white chocolate is one of the the silkiest, creamiest not to sweet white chocolate it gives  a rich mouthfeel that never ever becomes too heavy when making this  ganache. Avoid using Valrhona 35% or any chocolate with more than 32% cocoa solids, as it thickens the pistachio ganache too much, making it grainy and hard to spread. Still want to use Valrhona 35%? You need to reduce the amount of white chocolate to 200 grams, or even down to 150 grams, instead of the usual 300 grams. 
   
• Coarsely chop 300 grams of white chocolate with a serrated knife, no need if using Callebaut Velvet 32% as they are small enough.
   
• Place the chopped white chocolate /callets into a heat-proof glass or measuring mug and set it aside.
   
• In a medium saucepan, combine 500 grams of heavy cream and 300 grams of homemade pistachio paste. Whisk to combine. Because there’s a lot of pistachio paste in this recipe, stir constantly with a spatula in all cornes of your saucepan while warming the mixture to prevent burning, always stay with the saucepan. 
   
• Gently heat the cream and pistachio paste over medium-low heat, stirring continuously until the paste is fully dissolved. Scrape the bottom and sides of the saucepan to prevent the mixture from burning. Increase the heat to medium and continue stirring, making sure to reach all corners of the saucepan. Heat the mixture to 65-70°C (149-158°F).
   
• Once the mixture reaches 65-70°C, pour it over the chopped white chocolate.
   
• Let the mixture sit for 1 minute before stirring. Then, stir slowly with a silicone spatula until smooth, ensuring the cream, pistachio paste, and white chocolate are fully combined. Scrape the sides and bottom of the bowl to incorporate all the chocolate. 
   
• Use an immersion blender to blend the mixture until completely smooth. If you don't have an immersion blender to blend the ganache, you can use a regular blender instead. If your blender isn’t already cleaned up, you can simply pour the mixture back into the blender and blend on low speed until the chocolate and everything is well combined.
   
• If small pieces of pistachio bother you, strain the mixture through a fine sieve. For the best taste, leave small pieces in, especially if the ganache is for inside a cake.
   
• Pour the warm pistachio ganache into a clean bowl or container and cover the top with plastic wrap against the surface. 
   
• Refrigerate overnight to firm up and deepen the pistachio flavors.
   
• Baker's Note: Fridge placement matters. The coldest parts, often at the bottom or near the back, can cause uneven cooling or rapid cooling, leading to a grainy or too-firm texture. Place your unwhipped ganache in the middle of the fridge for consistent temperature. The fridge should be cold, but not freezer cold. If it’s too chilly, the ganache can set too hard, leading to a grainy texture. Allow it to cool gently for a smooth, silky texture.
   
• Baker's Note:  When whipping this pistachio ganache if you are going to use it to fill your sponge cake with, it's best to whip it to a soft consistency or soft medium consistency, which can take anywhere from 10 to 50 seconds. Although you might think it doesn't seem firm, it should be almost like the consistency of whipped cream. Place it in an airtight container with plastic wrap on top, and when you're ready to fill your cake, it will spread beautifully. If you over whip it to medium or stiff peaks, it will be very difficult to spread smoothly in your cake. Whipping it to soft medium peaks will also give your cake a much better mouthfeel when you enjoy it this ganache inside your cakes.
   
• Pour the pistachio ganache into a stand mixer fitted with the whisk attachment. Whip at medium speed until you reach soft medium peaks—this usually takes about 10-50 seconds. Stop every 20 seconds to check the consistency. To prevent over whipping.
   
• Store the soft or soft-medium peaks whipped ganache an airtight container in the refrigerator with plastic wrap against the surface of the cream until you are ready to fill your cake. This ensures it’s ready for easy piping or smooth spreading. A softer consistency makes decorating a breeze.
• Baker's Note: The first time I made this pistachio ganache, it tasted amazing, but I noticed a slight graininess. This isn't due to overmixing; it's because pistachios naturally have a bit of texture. When using homemade pistachio paste, there will always be a hint of the pistachio texture in the ganache. I don't want to change the recipe because it is so delicious. Especially if you’re using this ganache inside a cake, the texture won't matter—it's just so awesome. You will see a little bit of the pistachio texture, but I guarantee it's 100% delicious.

Raspberry Jam
 

• In a medium-sized saucepan, combine 250-gram frozen raspberries, two teaspoon cornstarch, 1 tablespoons sugar, and 35 gram freshly pressed lemon juice.
   
• Heat the mixture on medium-low heat and bring to a simmer to soften the raspberries for about 5 to 10 minutes. Make sure to stir at times.
   
• Cool the raspberry jam at room temp, then refrigerate for at least 1 hour or until cool to the touch. The raspberry jam will thicken as it sits in the fridge.

Greek Yogurt & Raspberry Filling

• Baker's Note: Use only heavy cream (or heavy whipping cream) with a 40% fat content. This higher fat content is key for whipping up this Greek Yogurt Cream that's both thick and stable, providing the perfect base for your frosting. Ensure the cream is very cold for optimal whipping; placing the cream in the freezer for about 15 minutes before use can enhance the whipping process.
   
• Bakers Note: Make sure to use full-fat, natural Greek-style yogurt with a 10% fat content. The thick consistency of Greek yogurt, achieved by straining out the whey, makes it an ideal choice for creating a rich and creamy Whipped Yogurt Frosting. Avoid low-fat or fat-free yogurts, as their higher water content can result in a frosting that's too runny. If your Greek yogurt is too watery, strain it through a fine-mesh sieve over a bowl, cover with plastic wrap, and let it drain in the fridge for a few hours or overnight. This step ensures your frosting achieves the perfect consistency, avoiding a watery outcome that could compromise its structure.
   
• In a stand mixer fitted with the whisk attachment, beat together 55-gram powdered sugar, 250-gram cold Greek yogurt, 250-gram cold heavy cream, 1 to2  teaspoon of vanilla bean paste.
   
• Mix on medium-high speed until light, fluffy and thick. It takes about 1-3 minutes. Whipped yogurt frosting destabilizes (softens) when overmixed, so keep an eye on the frosting as soon as it thickens. When you remove the bowl from the mixer, use your spatula to scrape the sides and bottom of the bowl to ensure that your Greek yogurt frosting is thick.
   
• Take the cold raspberry jam out of the fridge and add it to the Greek Yogurt frosting a little at a time. Be mindful to avoid deflating the filling too much. Some deflation is expected, especially if you want a lot of raspberry jam/flavor  in the filling. It’s important to use 40% fat content cream when making this filling; otherwise, it will deflate even more. If you didn't use 40% but let say 35% heavy cream, you can add a tablespoon of raspberry jam directly on top of the Greek yogurt inside the cake instead.
   
• I typically add about half of the cold raspberry jam (approximately 100 grams) and then combine it with the Greek Yogurt frosting. The mixture will become loose when mixed, but it will firm up inside the cake, so don’t worry about that.
   
• Building the Cake: It’s always better to build the cake inside a cake ring to ensure stability and prevent spillage. Although I sometimes build my cakes outside a ring for video demonstrations to show the process clearly, I prefer using a cake ring for stability.

Assemble  Raspberry Pistachio Cake

• Gather all the components for your cake (pistachio sponge cake layers, cold raspberry jam, whipped pistachio ganache, and the raspberry Greek yogurt filling).
   
• Place the first cake layer, cut side up, on a cake plate that fits in the fridge or inside a cake ring.
   
• Spread a few tablespoons of raspberry jam over the cake layer using an offset spatula, smoothing it out evenly to cover the entire layer. This will help moisten the cake.  Add one-third of the whipped pistachio ganache on top of the raspberry jam, spreading it to the edges.
   
• Place the second cake layer on top and press it down gently to ensure it holds together better when cut. Spread a little less than half of the raspberry Greek yogurt filling over this layer.
   
• Add the third cake layer and press it down gently. Spread about one-third of the raspberry Greek yogurt filling on top. If you still have some raspberry jam left, you can add a bit between the raspberry Greek yogurt filling and the pistachio ganache. Spread another one-third of the pistachio ganache on top of the raspberry Greek yogurt filling. Place the final cake layer on top and press it down gently.
   
• Cover the entire cake with plastic wrap. Press the top down gently while you wrap the cake in plastic wrap to ensure they hold together. No need to add something heavy on top.
   
• Place the cake in the fridge for at least 8 hours or overnight to set.
   
• Before serving, remove the plastic wrap. This cake is so delicious with an explosion of pistachio and raspberry flavors that I didn't feel the need to frost the outside. However, if you want to frost the outside, a little whipped cream combined with raspberry is a great match. You can check the frosting category in my app for many fruity frostings to fill this cake with. I enjoyed it as a naked cake because there’s so much flavor that I couldn't get enough. It’s so delicious. I hope you love it as much as I do.