Checkerboard Cake

Ingredients

• Cake
• 3 ounces dark chocolate
• 2 tablespoons unsweetened cocoa powder
• 1 cup butter, at room temperature
• 1 1/2 cups sugar
• 5 eggs
• 2 teaspoons vanilla
• 1 1/2 cups buttermilk
• 3 1/4 cups all-purpose flour
• 1 tablespoon baking powder
• 1 teaspoon baking soda
• 1 pinch salt
• Filling
• 10 ounces dark chocolate
• 1 cup whipping cream