Coconut Birthday Cake - cooking recipe

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

Preparation

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.