Moist Vanilla Bean Cake with Creamy Buttercream

Instructions

1. 1

   Combine the vanilla extract, vanilla bean paste, and sour cream in a bowl and let sit for 10 minutes to allow the flavors to meld.

2. 2

   Sift together the cake flour, sugar, baking powder, and salt twice to ensure no lumps. Add the canola oil and softened butter and beat until crumbly. Add the egg whites one at a time, beating well after each addition, then add the whole eggs one at a time, beating well. Finally, add the sour cream and vanilla mixture and beat until just combined.

3. 3

   Grease and line three 9-inch cake pans with parchment paper. Divide the batter evenly between the pans and bake at 350°F for 30-35 minutes, until a toothpick inserted in the center comes out clean. Allow the cakes to cool in the pans for 10 minutes, then turn out onto a wire rack to cool completely before frosting.

4. 4

   Make the Swiss meringue buttercream frosting by melting white chocolate chips with cream, then stirring in the vanilla paste and extract. In a heatproof bowl, whisk the egg whites, sugar, cream of tartar, and salt over a saucepan of simmering water until the mixture reaches 160°F, about 6-8 minutes. Remove from heat and beat on high speed until cooled to 90°F, about 7 minutes. Gradually beat in the butter, then the cooled white chocolate mixture.

5. 5

   Level the cake layers if needed, then place the first layer on a cake stand or plate. Spread frosting between the layers, then do a thin crumb coat around the outside. Finish by frosting the cake as desired, using swirls or piping for a decorative touch.