Devil’s Food Layer Cake

INGREDIENTS

• 3 eggs
• 1 cup boiling water
• 3/4 cup unsweetened natural cocoa powder
• 1 3/4 cups all-purpose flour
• 1 1/2 tsp. baking soda
• 1/4 tsp. fine sea salt
• 2 cups granulated sugar
• 10 Tbs. (1 1/4 sticks) unsalted butter, at room temperature
• 1 tsp. vanilla extract
• 1 1/4 cups buttermilk
• 3 3/4 cups confectioners’ sugar
• 1 cup unsweetened natural cocoa powder
• 8 Tbs. (1 stick) unsalted butter, at room temperature
• 1 cup heavy cream, or as needed