Coconut Birthday Cake - Cake

Method

• I would recommend starting this cake a day or so in advance of serving so that you can allow the assembled cake at least 24hrs to meld in the refrigerator before serving.
• For the Cake:
• Adjust the oven rack to the lower-middle position and preheat to 325 degrees. Grease and flour (2) 9" cake pans.
• Whisk the egg whites and egg in a bowl to combine. Add the cream of coconut, water, vanilla, and coconut extract. Whisk until thoroughly combined.
• Combine the flour, sugar, baking powder, and salt in the bowl of a stand mixer fitted with the whisk attachment. Mix on the lowest speed to combine, about 30 seconds.
• With the mixer still running, add the butter 1 tablespoon at a time until the mixture resembles coarse meal.
• Then with the mixer still running, add 1 cup of the liquid. Increase the speed to medium-high and beat until fluffy, about 45 seconds. Add the remaining liquid in a steady stream until combined.
• Divide the batter between the two cake pans and level the pans with a spatula.
• Bake until a toothpick comes out clean, about 30 minutes.
• Cool in the pans on wire racks for about 10 minutes, then loosen the cakes from the pans and place top sides up on a cooling rack and cool to room temperature.
• For the Filling:
• Stir the cornstarch, water, and vanilla in small bowl to dissolve the cornstarch.
• Bring the cream, sugar, and butter just to a boil in a heavy medium saucepan. Add cornstarch mixture and bring back to a boil.
• Remove from heat and stir in coconut. Cool completely.
• Mix in the sour cream. Cover and refrigerate.
• For the Frosting:
• In a large bowl, combine the egg whites and the sugar and whisk until well blended. Set the bowl on top of a double boiler, or transfer mixture to the top pan of a double boiler and whisk constantly until the mixture is hot to the touch and the sugar is thoroughly melted.
• Transfer to the egg and sugar mixture to a stand mixer and beat on High with the whisk attachment until the bowl has cooled to the touch and the meringue forms stiff peaks.
• While beating on medium speed, slowly add the room temperature butter, about 1/4 cup at a time until thick and creamy. Add the vanilla and blend until combined.
• The frosting can be made in advance and refrigerated until ready to use.
• For the coconut topping:
• Spread out on a cookie sheet and bake in a 350 degree oven until light golden brown. Allow to cool thoroughly.
• To assemble the cake:
• Using a knife, dental floss (the non-mint kind) or a cake wire, slice each cake into two layers so that you have 4 layers of cake.
• Put a dab of frosting on your cake plate so that the bottom layer does not move around.
• Place one of the cake bottoms on the cake plate and use the butter cream to create a 'lip' around the edge of the cake. This will prevent any filling from oozing over the edge of the cake when you put the layers together.
• Spoon one-third of the filling onto the cake and spread evenly.
• Continue with the remaining layers, finishing with a cake top for the top layer.
• Frost with the vanilla buttercream and don't worry if it isn't perfecly smooth since you're going to be pressing coconut on top.
• Next, press the toasted coconut onto the sides and top and refridgerate at least 24hrs before you serve the cake.