Petit Champagne Layer Cakes

Name: Petit Champagne Layer Cakes
Ingredients: Champagne Angel Food Cakes; 1 cup Cake Flour; 1 1/2 cups Confectioner's Sugar; 1 1/2 cups Egg Whites; 1 1/2 teaspoons Cream of Tartar; 1 cup Granulated Sugar + more for coating pan; 1/4 cup Champagne; 2 tablespoons Unrefined Coconut Oil (for coating pan); Champagne Swiss Meringue Buttercream; 6 Egg Whites; 1 3/4 cups Granulated Sugar; 1 teaspoon Salt; 1/2 teaspoon Cream of Tartar; 1/2 tablespoon Vanilla Extract; 32 tablespoons Butter, softened; 1/2 cup Champagne