Vanilla-infused Cream.
 

• Note, The cake batter recipe needs 350 grams of vanilla-infused cream, but If you warm only 350 grams, you won’t have enough because you will lose some evaporation. That´s why in the case of this cake, heat 400 grams of heavy gram with the vanilla bean.
   
• Use a sharp knife to split the fresh vanilla bean lengthwise and scrape the vanilla caviar seeds into a medium saucepan. Put the pod in the saucepan as well.
   
• Pour heavy cream into the saucepan. ( if using vanilla bean paste, add that instead) give it a little whisk.
   
• Place the saucepan over low-medium heat until warm but not boiling.
   
• Remove from heat, cover, and let steep at room temp for 1 hour if time permits (optional); otherwise, proceed as directed.

Directions for the vanilla cake layers

 

• Preheat the oven to 165C°/325F° 30 minutes before baking.
   
• Brush 2 x 20 cm ( 8- inches) round baking pans with softened butter, add one tablespoon of flour in each baking pan and tap around the pan until all the buttered surface is covered. Then turn the pan upside down over a sink, tap out the excess flour, and apply a parchment circle to the bottom. 
   
• Before you start making the cake layers, → Make sure the diced butter has a temperature of 18C°/65F°. The → vanilla-infused cream 21C°/70F° and sour cream if using, need to be 21C°/70F°, and the egg whites need to be at 21C°/70F° before you start the cake. It´s *that* important in this recipe! I prefer using a digital thermometer. If your ingredients are not at the right temperature, as mentioned, your cake can become too dense or even give a gummy layer along the bottom of the cake. Again, using a digital thermometer is the best way to know.
   
•  Add the 300-gram cake flour, 400-gram superfine sugar, 15-gram baking powder, and a pinch of salt into a stand mixer bowl fitted with the whisk attachment, and mix on low speed for about 1 minute.
   
• With your mixer at low speed, add the 170-gram unsalted butter one piece at a time, about every 10 seconds. 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.
   
• Discard the vanilla bean from the heavy cream ( make sure you squeeze out all of the gooey vanilla seeds and add them back into the cream) and give it a quick whisk. Make sure the vanilla-infused cream is at the right temperature and weighs 350 grams. Add 40-gram sour cream if using, and give it a quick whisk.
   
• *Note when it is time to add the 350-gram vanilla-infused cream, you want to add the cream a little at a time and make sure you’re maintaining the smooth emulsion the whole time. Please make sure the cream is at room temp and add it in small increments and mix on medium-low speed until smooth. You don't want to add the cream at once, or the fat won't be able to trap it, and the batter will look curdled.
   
•  With the mixer on low, slowly pour in the 350 gram vanilla-infused cream in small increments, a little at a time, then continue mixing on medium speed (speed four on KitchenAid) for two full minutes to develop the structure. Set a timer! Do not overmix for just 2 minutes, not any longer!
   
• You should still have a lot of flavorful vanilla seeds left in the bottom of the vanilla-infused cream bowl, don't forget to scrape all the flavorful seeds into the cake batter as soon as you have mixed for 2 minutes.
   
• The batter should have gained volume at this point and have a texture like a thick buttercream, and all the ingredients should be incorporated at this stage. 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 mine.
   
• 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.
   
• From this point, you need to mix as lightly and little as I mention.
   
• Attach your whisk attachment again, starting at medium-low speed. Gradually add the 210-gram egg whites to the batter in three separate parts, beating on medium speed for 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, scrape down the side and bottom of the bowl, remove the whisk attachment, and shake out the excess batter collected inside.
   
• Stop the mixer and scrape down the side and the bottom fold once or twice to ensure the batter at the bottom of the mixing bowl is incorporated. 
   
• Evenly divide the cake batter among the two prepared pans, spreading evenly with a spatula. If time permits, let the cake batter rest in the pan for 20 minutes before baking ( optional, but it makes your cakes layers magical)
   
• Bake in the bottom third of the oven until a cake tester/toothpick inserted in the center of the cakes comes out with just a few moist crumbs, about 25 to 35 minutes.
   
• Allow the cakes to cool in their pans for about 15 minutes. Then, using a knife, loosen the sides of the cakes and carefully turn them out onto a wire rack, peel the paper liners, and let them cool completely.
   
• Once the cake layers are completely cooled, wrap each cake layer tightly in plastic wrap until you decorate the cake.
   
• It is best not to refrigerate butter cake layers since the butter hardens when cold and makes the texture of the crumbs too dense. Instead, wrap the cooled cake layers in plastic wrap at room temperature for up to 2 days.
   
• Make sure your cake layers are cooled completely before frosting/decorating your cake.
   
• I prefer to trim the crust of the vanilla cakes. This is optional. I feel it gives the cake a more nice feel in the mouth. If you want to remove the crust, use a sharp knife and carefully trim all the sides. Make sure to cover the trimmed cake layers with plastic wrap to ensure they stay soft and tender while preparing the coffee latte buttercream.

Coffee Latte Buttercream

• Coffee, I make my coffee in my espresso machine to get the best coffee flavor. You can also use one teaspoon of instant espresso powder with hot water to make a strong coffee taste depending on how much coffee flavor you like in your buttercream. You want it to be strong but not overly strong. It all has to be in the right balance.
   
• If using a food processor, Put 300-gram confectioner's sugar ( or powdered sugar), 200 grams cold salted butter or unsalted butter ( in small pieces/cubes), two teaspoons vanilla bean paste into a food processor, blend/pulse while slowly drizzling in the warm coffee if using unsalted butter add a pinch of sea salt. Beating until smooth, about 60 to 90 seconds.
   
• Scrape the side and bottom of the food processor with a silicone spatula, make sure the buttercream is smooth and lump-free, then place the lock back on and blend/pulse while slowly drizzling in 60-gram cold heavy cream, pulsing for about 30 seconds, scrape the side and the bottom of the bowl to ensure the buttercream is 100% lump-free.
   
• Your Coffee Latte Buttercream is ready to use; For ideal spreading consistency, it is best used right away to spread onto your cakes.
   
• The buttercream will keep in an airtight container in the fridge for up to 3 days.
   
• To make the frosting smooth again, pulse in your food processor to bring it back to a spreadable consistency or let the buttercream come back to room temperature and beat on low speed in your stand mixer using the paddle attachment.
   
• If using a stand mixer, In the bowl of an electric mixer fitted with the paddle attachment, Put 200 gram cold salted butter or unsalted butter ( in small pieces/cubes), and 30-gram strong warm coffee on top of the butter, let sit for a minute, then beat on low speed until smooth—about 1 minute. With the mixer still on low speed, gradually add the 300-gram confectioner's sugar, two teaspoons of vanilla bean paste, and a pinch of sea salt if using unsalted butter.
   
• With your mixer at low/medium speed, beat until light and fluffy, about 3 to 5 minutes.
   
• Scrape the side and the bottom of the bowl, as well as your paddle attachment. Then mix again with your mixer at low-speed, drizzle in the 60 grams of cold heavy cream, and mix until fluffy, about 30 seconds.
   
• Your Coffee Latte Buttercream is ready to use; For ideal spreading consistency, it is best used right away to spread onto your cakes.
   
• The buttercream will keep in an airtight container in the fridge for up to 3 days. Then, let the buttercream come back to room temperature using your stand mixer and paddle attachment and beat on low speed to make the frosting smooth again to bring it back to a spreadable consistency.

Assembling the cake layers
 

• Place the first cake layer on a cake stand, spread a few dollops of the coffee latte buttercream on top, Use an offset spatula, and spread into an even layer of frosting on the cake layer.
   
• Add 100-gram fudge brownies ( I use frozen brownies bites size) on top of the frosting, and add a little more buttercream on the brownies to ensure the cake layers stick together.
   
• Place the final cake layer on top, and press down gently to help the layers stick together.
   
• Use an offset spatula to apply the rest of the buttercream to the top of the cake, and spread it into an even layer. 
   
• For maximum freshness and deliciousness, Serve on the day this cake is made. The cake tastes best if you let rest for 1 to 2 hours before serving it under a cake dome at room temperature.
   
• Store leftovers under a cake dome at room temp for up to 24 hours.
   
• If you prefer to store the cake in the fridge, allow the cake to stand at room temperature for at least 2 hours before serving.