Bourbon Layer Cake with Bourbon Ganache and Milk Chocolate Buttercream

INGREDIENTS

• For Cake:
• 1 vanilla bean split and scraped, seeds reserved
• 1/2 cup (4 ounces) bourbon
• 2 cups (13.5 ounces) all purpose flour, sifted
• 1 tablespoon baking powder
• 3/4 teaspoon baking soda
• 1 teaspoon salt
• 1 3/4 cup granulated sugar
• 1/2 teaspoon freshly grated nutmeg
• 1 cup (2 sticks) unsalted butter, room temperature
• 5 eggs, room temperature
• 2 egg yolks
• 1 1/2 cups buttermilk
• For Buttercream:
• 4 ounces dark chocolate
• 6 ounces milk chocolate
• 2 cups (4 sticks) unsalted butter, room temperature
• 2-3 cups powdered sugar, or more as needed
• 1/4 cup heavy cream
• 1 teaspoon vanilla extract
• For Ganache:
• 4 ounces dark or semisweet chocolate, finely chopped
• 1/2 cup heavy cream
• 1 tablespoon bourbon