Coconut Birthday Cake

Ingredients

• Cake
• 1 egg
• 5 egg whites
• 3/4 cup cream of coconut
• 1/4 cup water
• 1 teaspoon vanilla extract
• 1 teaspoon coconut extract
• 9 ounces cake flour, sifted
• 1 cup sugar
• 1 tablespoon baking powder
• 3/4 teaspoon salt
• 12 tablespoons unsalted butter, room temperature
• Filling
• 2 tablespoons cornstarch
• 3 tablespoons water
• 1 teaspoon vanilla extract
• 1 1/4 cups whipping cream
• 1/2 cup sugar
• 1/2 cup unsalted butter
• 2 1/4 cups sweetened flaked coconut
• 1/4 cup sour cream
• Frosting
• 1/2 cup egg white, at room temperature (from approx 4 large eggs)
• 1 cup sugar
• 1 lb unsalted butter, room temperature
• 1 teaspoon vanilla extract
• Coconut topping
• 2 cups sweetened flaked coconut