This White chocolate Raspberry Cake features layers of fluffy vanilla cake filled with raspberry compote, whipped white chocolate ganache, and covered in a dreamy raspberry white chocolate buttercream.
Start by making the whipped white chocolate ganache. Add heavy cream to a large glass measuring or medium bowl. Warm in the microwave for 1 minute. Chop the white chocolate and add it to the warmed heavy cream. Let it sit for 2-3 minutes, then stir together until the white chocolate is fully melted and the mixture is smooth. (If it's not fully melted, microwave in 15 second increments until fully melted, stirring between each time). Place the bowl into the refrigerator to cool completely (this will take about 2-3 hours and should be ready by the time the cake is ready to assemble). 8 oz White Chocolate1/2 cup Heavy Cream
Now make the raspberry compote filling. Add raspberries, sugar, and lemon juice to a medium saucepan over medium heat. Cook for 10 minutes, then reduce heat to medium low and continue to cook for 15-20 minutes, stirring occasionally, until the mixture reduces and thickens slightly. Mix together cornstarch and water in a small bowl, then add the cornstarch slurry to the raspberry mixture. Stir for 3-4 minutes, until the raspberries become jammy. Remove from heat and place into a small bowl to cool completely. It'll thicken more as it cools. (you can also place this into the refrigerator) 3 cups Raspberries1/2 cup Sugar 2 tbsp Lemon Juice 1 tbsp Cornstarch1 tbsp Water
Let's get started on the cake. Preheat the oven to 350 degrees F. Brush 3 8-inch pans with melted butter, then dust with flour, ensuring the entire pan is coated. (you can also use nonstick baking spray but I've found that brushing the pans and coating with flour is most reliable and prevents the outside of the cake from browning too much)
In a large bowl, whisk together cake flour, baking powder, and kosher salt. Set aside. 3 cups All Purpose Flour1 tbsp Baking Powder1 tsp Kosher Salt
Add room temperature butter, vegetable oil, and sugar to the bowl of a stand mixer fitted with the paddle attachment. Mix together on medium speed for 3-4 minutes, until smooth and fluffy, also slightly lightened in color (should be a pale yellow). 1/2 cup Salted Butter1/2 cup Vegetable Oil 2 1/4 cups Sugar
Scrape down the sides of the bowl with a rubber spatula. Reduce mixer speed to low and begin adding eggs, ensuring each egg is fully incorporated prior to adding the next. Then add all of the egg whites and mix until combined, scraping down the sides of the bowl as needed. It'll take about 1 minute for the egg whites to become fully incorporated into the butter mixture so be patient. Add in vanilla bean paste (or exact) and almond extract and mix to combine, about 15 seconds. 3 large Eggs3 Egg Whites 1 tbsp Vanilla Bean Paste 1 tsp Almond Extract
Add half of the dry ingredients to the wet ingredients and mix until just combined, about 20 seconds. Then add in whole milk, heavy cream, and sour cream. Continue to mix until combined, then add the remainder of the dry ingredients. Mix until smooth, about 20 seconds. Scrape down the sides and bottom of the bowl, ensuring that all of the ingredients are fully incorporated. 3/4 cup Whole Milk1/4 cup Heavy Cream1/2 cup Sour Cream
Divide batter equally among the 3 prepared cake pans and bake on the middle rack of the oven for 28-32 minutes, until a toothpick inserted into the center of each cake comes out with just a few moist crumbs. Allow the cakes to cool in the pan for 10 minutes, then turn over onto a wire rack. Cover with plastic wrap and to cool completely. (this traps in steam and keeps the cake super moist)
While the cake is cooling, make the buttercream. Chop up the white chocolate and add to a small microwaveable bowl. Microwave for 30 seconds. Stir, then microwave again in 15 second increments until fully melted, stirring between each session - be careful not to burn the chocolate. Once it's almost completely smooth, set aside to cool for 15 minutes. 4 oz White Chocolate
Wash out the bowl of the stand mixer and place it back onto the stand mixer with the paddle attachment. Add room temperature butter and beat on medium high speed for 5 minutes. Add in 2 cups of the powdered sugar and the melted white chocolate and beat on low speed, gradually increasing to medium high speed once combined. Beat for about 1 minutes, then add the remaining powdered sugar, vanilla bean paste (or extract), whole milk, and 2 tbsp of the cooled raspberry filling. Start on low speed, then gradually increase to medium high speed. Mix on medium high for 2 minutes then scrape down the sides of the bowl and continue to mix for 30 seconds, ensuring the buttercream is smooth and combined. 1 1/2 cups Salted Butter4 cups Powdered Sugar 1 tbsp Vanilla Bean Paste 2 tbsp Whole Milk2 tbsp Reserved Raspberry Puree
Remove the chilled white chocolate mixture from the refrigerator. Use an electric hand mixer to beat until fluffy and creamy, about 3-4 minutes. It should be the texture of a thick mousse.
Now let's assemble the cake. Fill a pastry bag (you don't need a piping tip but feel free to use one) with the raspberry buttercream. Place one cake layer onto a cake stand. Spread half of the whipped white chocolate ganache on top.
Using the piping bag, pipe a border the perimeter of the cake, then add half of the raspberry filling on top. Repeat with the second layer.
Place the third cake on top then cover the cake with a thin layer on buttercream. Place the cake into the refrigerator to set for 30 minutes. (This is the crumb coat aka the first layer of frosting that seals in any loose crumbs, allowing for the second layer to be smooth)
Remove the cake from the refrigerator and cover with the remaining buttercream and top with any leftover raspberries.