Baker Note; For the Vanilla Sheet cake,  I opt to create three equal vanilla cake layers and fill the cake with a layer of blackcurrant jam and blackcurrant whipped cream or layers of Blackcurrant poppyseed Whipped Cream for added indulgence. However, for a simpler version, feel free to spread the Blackcurrant Poppy Seed Whipped Cream right on top of the sheet cake. Both methods are delicious—it's all about what you're in the mood for!

In the 'Love Manuela' app, you'll find a helpful section labeled 'Note'. just beside this page. This section includes a clickable link that leads you to a gallery of step-by-step photos. These images visually guide you through the process of making both these cake, providing clarity and inspiration.
 

Vanilla sheet cake
 

• 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. 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.
   
• Adjust the oven rack to the bottom third of the oven and preheat the oven to 350F° (170C°) 30 minutes before baking. 
   
• Bakers note; Working with semi-cold butter produces a better cake texture; if the butter is too soft, it essentially melts into the flour, which can result in a greasy cake. The butter needs to be pliable (slightly softened) but cool. Take it out of the fridge for about 20 minutes before you bake this cake. The right temperature is 18C°/65F°. “Precision is key in achieving the perfect texture and flavor.
   
• Baker's Note: Using a digital laser thermometer ensures your butter, egg whites, and Greek yogurt cream mixture are at the ideal temperatures for a flawless result. If yours are too cold or too warm, the cake batter will go from smooth and creamy to looking split and clumped. The cake might turn out okay, but the texture will be affected and may not be as tender and moist as you'd like.
   
• Brush the inside of a 23 cm x 32 cm ( with 5 cm tall sides) ( 9 x 13-inch x 2-inch) baking tray with softened butter, and place parchment paper in the baking tray, set aside for now. 
   
• Pour 250 grams of heavy cream and one teaspoon of vanilla bean paste into a medium saucepan. If using a vanilla bean in this recipe, run the flat side of the blade down each half to scrape out the seeds and add them to the cream. Add the pod in there as well for extra flavor. For the best vanilla flavor in your vanilla sheet cake, make sure to steep the vanilla bean/pod in the cream for at least one hour before you proceed to bake the cake; I know it's an extra step, but it will make all the difference taste-wise in your vanilla sheet cake.
   
• Bring to a simmer. Remove from heat, cover tightly, and steep for 1 hour. Remove the vanilla pod, scrape the flavorful goo back into the cream as well as the pod, and return to a simmer. To avoid having to wait for the vanilla-infused cream to cool down to the right temperature, stir 100 grams of semi-cold Greek yogurt in the cream mixture, lowering the temperature so it is almost good to go when it is time to add the cream mixture.
   
•  Into a bowl of a stand mixer fitted with the whisk or paddle attachment, add 450-gram superfine sugar, 350-gram cake flour, a pinch of salt, and 15-gram baking powder. Let it spin for a few seconds to incorporate it together.
   
• Then add 175-gram pliable but still cool unsalted butter (18C°/65F° ) one piece at a time; once all of the butter is added, the mixture should resemble almond flour, and when you run your hands through it, it feels kind of sandy, and there should be no large lumps of butter left. This step takes about 2-3 minutes. Do not mix more than needed.
   
• Discard the vanilla bean from the heavy cream-Greek yogurt mixture (make sure you squeeze out all of the gooey vanilla seeds and add them back into the cream), and give it a quick whisk. Discard the vanilla bean pod. Double-check that the vanilla-infused yogurt cream is at the right temperature. It should be 23°C/73.4°F. Using a digital laser thermometer is the best way to know for sure.
   
• Baker's Note: In this next step, you need to add the cream/Greek yogurt mixture. Make sure to do this slowly to create the perfect emulsion. If you add it too quickly, your cream/yogurt will separate from the butter and sink to the bottom of the cake, giving you a gummy layer and creating a dense texture.
   
• With the mixer on low speed, very slowly pour in the 350-gram vanilla-infused yogurt cream a little at a time; this takes about 1 minute. Then continue mixing on medium speed (speed four on a KitchenAid) for 2 minutes to develop the structure. Set a timer!
   
• The cake batter should have gained volume at this point and should look like thick buttercream, with all the ingredients incorporated. If you don’t mix it for two full minutes, your cake could be under-mixed, collapse in the center, and won't be as tender and fluffy as you might like.
   
• Stop the mixer and scrape down the side and bottom of the bowl, remove the whisk attachment, and shake out the excess batter collected inside. 
   
• Attach your whisk or paddle attachment again, starting at low speed (speed two on a KitchenAid). Gradually add the 210-gram egg whites (23°C/73.4°F) to the batter in three separate parts, beating on medium speed for only 20 seconds each time (not any longer!) after each addition to incorporate the ingredients and strengthen the structure. Stop the mixer after each addition of egg whites, and scrape down the sides and bottom of the bowl. Also, remove the whisk or paddle attachment each time and shake out the excess batter that is collected inside.
   
• Stop the mixer and scrape down the sides and the bottom of the bowl, then fold once or twice to ensure the batter at the bottom of the mixing bowl is fully incorporated. At this stage, if you have followed every step correctly, the cake batter should look smooth; if not, I recommend leaving the cake batter on the kitchen counter for 20 minutes to allow the flour to hydrate (absorb liquid) before you proceed with the recipe.
   
• Pour the vanilla cake batter (about 1500 grams) into your prepared baking tray, spreading it evenly with an offset spatula to reach the corners. Spin the sheet cake tin on the table to settle it, but do not tap it on the table! 
   
• Bake immediately until a cake tester/toothpick inserted in the center of the vanilla sheet cake comes out with just a few moist crumbs. It takes about 30 to 35 minutes; Mine was done in 32 minutes. Don't over-bake the cake, or your cake will be dry; watch it carefully at the end; one minute too long can make a world of difference in your cake texture. I remove the cake from the oven when the toothpick still has moist ( not wet) crumbs attached; the heat from the baking tray will continue to bake the cake after it is removed from the oven. 
   
• Allow the vanilla sheet cake to cool in its baking tray.
   
• This next step is optional; I prefer to remove the crust on top of the vanilla sheet cake while the cake is still slightly warm, as it gives a clean look to the cake and a better mouthfeel! Trim the top of the vanilla sheet cake with a sharp knife while the cake is still in the baking tray, before frosting the cake. 
   
• I like to flip the vanilla sheet cake out of the baking tray; here's how I do it: Run a small offset spatula around the edges of the cake. Invert a flat wire rack over the sheet cake and, in one fluid motion, turn the vanilla sheet cake out onto the wire rack and remove the baking tray. Carefully peel the parchment from the bottom of the cake, invert another wire rack over the vanilla sheet cake, and, holding both sides of the wire racks (take a deep breath!), in one fluid motion, invert the vanilla sheet cake onto the other wire rack, so that the crust is now on top.
   
• Remove the crust on top of the cake with a sharp knife for a better mouthfeel. 
   
• Once the cake layer is completely cooled; Create three equal vanilla cake layers, you’ll need to make two cuts. Use a ruler to mark two points along the vanilla sheet cake’s surface at 10 cm and 20 cm from one edge. These marks will be your guide. Now, with a long serrated knife, gently saw at the first mark to cut the cake horizontally, working carefully to keep the layer even. Repeat this process at the second mark to create three equal layers of 10 cm each. 
   
• Wrap the cake layers tightly in plastic wrap until you are ready to decorate the cake. This keeps the cake layer soft and tender for at least 3 days.
   
• Make sure your vanilla sheet cake is 100% cooled before you fill the cake.

Blackcurrant  Compote/liquid 
 

• Place 250 grams of frozen blackcurrants, 1 tablespoon of sugar, 2 tablespoons of freshly squeezed lemon juice, and 1 tablespoon of water in a small saucepan. Gently cook on low heat until the berries soften and burst. Then, simmer on low heat for 10 minutes. Remove from heat.
   
• If filling the cake with jam and blackcurrant whipped cream, use a fork to gently break up the berries in the jam. This will help release more flavor and create a pleasing texture for the cake filling. Place the berry-filled jam in the fridge until it's completely cold. This step ensures the jam is at a good consistency for spreading on the cake layers and for the blackcurrant whipped cream.
   
• If opting for the Blackcurrant & Poppyseed Whipped Cream, strain the warm blackcurrant compote through a fine mesh sieve once it is cooked. Press on the solids to extract as much blackcurrant liquid as possible. For this recipe, you will need 100 grams of blackcurrant liquid. If you have any leftover liquid, consider making lemonade by adding sparkling water – it's delicious.

Blackcurrant & Poppyseed Whipped Cream
 

• If you're choosing to fill your cake with Blackcurrant & Poppyseed Whipped Cream, follow these steps. Otherwise, please scroll down to skip this section.
   
• Soak 2 gelatine sheets (3,2 grams) in very cold water until it is soft (this step takes at least 10 minutes). Use a timer!
   
• In a small saucepan, warm 100-gram blackcurrant liquid until warm.
   
• Squeeze excess water from the gelatine sheets and stir into the warm blackcurrant juice. Give it a quick whisk to melt the gelatin.
   
• Pour the warm blackcurrant gelatin mixture into a medium-sized bowl, add 1 to 2 teaspoons poppyseed (if using), stir to moisten the poppy seeds, and let the mixture cool down until lukewarm, 28C°/82,4F. This takes about 15 minutes.
   
• Bakers Tip; When you beat the cream in the next step, make sure to whip it at all times at medium speed and never at full speed (max 70%). For this recipe; you need to whip the cream until you get a softly whipped cream; By whipping the cream lightly until it soft peaks and adding gelatin, you retain the freshness of the cream at the same time. When you put the blackcurrant & poppyseed Whipped cream in your cake and place it in the fridge for a few hours, the gelatin does the job of making the cream just right.
   
•  In the bowl of a stand mixer, beat together 400 grams cold heavy cream, 1 to 3 tablespoons of superfine sugar, and 1 teaspoon of vanilla bean paste until you get a softly whipped cream. About 2 minutes.
   
• Baker tip; the thing to remember when you add the whipped cream to the blackcurrant gelatin mixture, it’s the setting action begins immediately. So work quickly!
   
• Stir one-third of the softly whipped cream into the lukewarm blackcurrant gelatin mixture and combine using a spatula until smooth, then gently fold in another one-third of the softly whipped cream and combine until smooth; repeat this step one more time. 
   
• Use immediately to fill your cakes with.
   
•  Keep leftovers in an airtight container in the fridge for up to 3 to 4 days, depending on the expiration date of your cream. If made with super-fresh cream, it will last for 3 to 4 days.  Re-whip lightly with a whisk to loosen it up before using.
   

Blackcurrant Whipped Cream
 

• If you're choosing to fill your cake with Blackcurrant jam and blackcurrant Whipped Cream, follow these steps. Otherwise, please scroll down to skip this section.
   
• In the bowl of a stand mixer, combine 400 gram cold heavy cream, 1-3 tablespoon superfine sugar, and  1 teaspoon vanilla bean paste. Beat the mixture on medium speed for about 3 minutes, or until you achieve medium stiff peaks. 
   
• Pull the cold blackcurrant jam from the fridge; Add one to three tablespoons of the cold blackcurrant jam to your already whipped cream. The exact amount can be adjusted to taste. Using a spatula, gently fold the jam into the whipped cream. Be careful not to overmix, as this can deflate the whipped cream. Aim for a uniform distribution of jam while maintaining the lightness of the whipped cream. After combining, if the mixture appears too loose or runny, place it back in the fridge. Chilling will help it firm up to the desired consistency. This method ensures a delightful blend of the rich flavor of blackcurrant jam.
   
• Place the bowl in the fridge until needed.
   
•  Keep leftovers in an airtight container in the fridge for up to 3 to 4 days, depending on the expiration date of your cream. If made with super-fresh cream, it will last for 3 to 4 days.  Re-whip lightly with a whisk to loosen it up before using.
   

Assembling Vanilla Sheet Cake
 

• Baker's Note: For the Vanilla Sheet Cake, create three equal vanilla cake layers. You can either fill the cake layers with a layer of Blackcurrant Jam and a layer of Blackcurrant Whipped Cream for added indulgence or simply spread the Blackcurrant Poppyseed Whipped Cream on both layers. Both methods are delicious—it depends on your preference! Please scroll further down for the version you want to assemble.
   
• Blackcurrant Poppy Bliss Version; Place the first cake layer on a flat surface or cake stand. Scoop and spread half of the Blackcurrant & Poppyseed Whipped Cream evenly across the layer using an offset spatula.
• Second Layer: Add the second cake layer on top and press down gently. Spread the remaining Blackcurrant & Poppyseed Whipped Cream evenly on this layer. Place the third cake layer on top and press down gently.
   
• Wrap the cake snugly in plastic wrap, then place it in a cake box or airtight container. Refrigerate for at least 4 hours.
   
• Before serving, let the cake come to room temperature for about 20 minutes. Slice into thick portions, and if desired, cut these into smaller pieces for serving.
   
• Blackcurrant Bliss Cake Version; Spread a few tablespoons of blackcurrant jam evenly over the first cake layer.
   
• Second Layer: Place the second cake layer on top and gently press down. Spread about half of the prepared blackcurrant whipped cream over this layer. Add the third cake layer on top and press down gently.
   
• Wrap for Freshness, Cover the cake in plastic wrap and store it in the fridge for a few hours to firm up.
   
• After chilling, remove the plastic wrap. Spread the remaining blackcurrant whipped cream thinly over the entire cake.
   
• The cake is now ready. Slice it into generous portions.
   
• Keep any leftovers wrapped in the fridge for up to 3 days.