Pistachio Layer Cake with Cream Cheese Buttercream

Instructions

• Preheat the oven to 350 degrees F (175 degrees C). Spray three 8-inch round cake pans with cooking spray. Line each pan with a round piece of parchment paper, and spray with cooking spray.
• Prepare the cake: pulse pistachios in a food processor until finely ground, 10 to 15 pulses. Transfer 1 1/2 cups ground pistachios to a bowl with flour, baking powder, salt, and baking soda; whisk until well combined and set aside. Place remaining ground pistachios, about 1 1/3 cups, in a bowl and reserve for finishing the cake.
• Beat butter and white sugar for cake in a stand mixer fitted with a paddle attachment on medium-high speed, scraping down the sides as needed, until light and fluffy, about 3 minutes. Add egg whites and beat on high speed until combined, about 2 minutes.
• Mix in sour cream, vanilla extract, and almond extract until combined, about 1 minute. Add flour mixture in batches on low speed until completely incorporated, about 2 minutes. Mix in milk and food coloring until just combined, about 1 minute.
• Divide batter evenly among the prepared cake pans. Gently tap each pan on the countertop to spread and flatten batter.
• Bake in the preheated oven until a toothpick inserted into the center of each pan removes cleanly, 22 to 24 minutes. Cool cakes in the pans for about 10 minutes. Run a table knife around the edges to loosen cakes, then invert carefully onto a serving plate or cooling rack. Let cool completely, about 30 minutes.
• While the cakes are cooling, prepare buttercream: beat cream cheese and butter in a stand mixer fitted with a paddle attachment on medium-high speed until light and fluffy, about 3 minutes. Mix in powdered sugar in 1/2-cup increments on medium-low speed, allowing sugar to be completely incorporated before adding more, until combined, about 4 minutes. Mix in vanilla and food coloring on medium-high speed until light and fluffy, about 2 minutes.
• Place one cake layer on a serving plate or cake stand. Top with 1 cup buttercream and 1 tablespoon ground pistachios, and spread evenly over the surface using a spatula. Place second cake layer on top; top with 1 cup buttercream and 1 tablespoon ground pistachios, and spread evenly over the surface. Place third cake layer on top, and spread 1 cup buttercream evenly over the surface. Spread 2 cups buttercream evenly around sides of assembled cake and smooth with a spatula. Transfer cake to the refrigerator and chill for 30 minutes.
• Remove cake from the refrigerator and spread remaining buttercream over top and sides of cake until sides are smooth and top is billowy. Using a small offset spatula, make a spiral pattern on top of the cake. Press remaining ground pistachios into sides of the cake.
• Slice and serve immediately or chill in an airtight container until ready to serve. If chilled, allow cake to come to room temperature before serving.