Ingredients
Preparation
30 minutes 1 hour 45 minutes
Step 2
With the motor running, add ¾ cup (1½ sticks) unsalted butter, room temperature, cut into pieces, then increase speed to medium and beat until butter is in small pieces and mixture looks sandy, about 3 minutes.
Step 3
Turn off mixer and add 4 large eggs, room temperature, 2 large egg yolks, room temperature, 1½ cups buttermilk, room temperature, and 1 Tbsp. vanilla extract. Beat on medium-high speed until pale yellow and fluffy, about 1 minute (be careful not to overmix batter). Divide batter between prepared pans and smooth tops with an offset spatula.
Step 4
Bake cakes until tops are golden and spring back when gently pressed, 30–35 minutes. Transfer pans to a wire rack and let cakes cool in pans 15 minutes. Run a small knife or offset spatula around inside of pans to loosen cakes, then turn out onto rack. Remove parchment and let cakes cool completely, about 1 hour.
Step 6
Using a large serrated knife, slice domed tops from cakes. Place 1 layer on a large plate or cake stand and spread a thick layer of frosting on top with an offset spatula. Place second cake layer on top and generously frost top and sides of cake with remaining buttercream. Smooth sides and create decorative swoops and swirls on the top.
