Preheat oven to 350°F (175°C).

Line bottoms of two 8-inch round baking pans with parchment paper and grease.

In a large bowl, combine white cake mix, coconut milk, eggs, and melted butter.

Beat on low speed for 30 seconds, then on medium speed for 1 1/2 minutes.

Pour batter into prepared pans.

Bake according to cake mix package directions and cool completely.

For the frosting, in a small saucepan, combine cubed butter, chopped white chocolate, and coconut milk.

Heat and stir over medium heat until smooth and blended.

Remove from heat and gradually stir in sifted confectioners' sugar until smooth.

Transfer frosting to a bowl.

Place the bowl in an ice-water bath.

Using a hand mixer, beat the frosting on high speed for 6-8 minutes, or until spreadable.

Spread frosting between cake layers, over the top, and sides of the cake.

Cover the cake with unsweetened coconut flakes.