Mix ingredients using the mixing times listed on cake mix box.
Divide batter equally between all 3 pans. The batter will be thick and may have to be spread outward to the edges with a spatula.
Bake at the temperature stated on box for 20 minutes or until toothpick is clean when removed.
Cool cakes for 5-10 minutes. Remove from pans. Let the cakes cool to the touch. If the cakes, have rounded tops, cut the tops off Brush off all crumbs and loose bits of cake.
Open the coconut milk and stir to mix the thick cream and milk together before using. If it needs to be thinned, add a little water. Brush the top of each cake with the coconut milk, then refrigerate.
Mix sour cream and sugar together by hand. Gently fold in the Cool Whip. Do not over stir.
Stack your cakes, putting a generous amount of icing and a light sprinkle of coconut between each layer.
Add just enough icing on top and sides for a crumb layer, then refrigerate for 20-30 minutes. (Refrigerate unused icing too.)
Line a baking sheet with parchment paper. Sprinkle a handful or two of coconut in a single layer on the baking sheet. Place under the broiler to lightly toast. When coconut is lightly golden, pull it from the oven and set aside to cool.
Pull your cake back out of the fridge and finish icing it.
Lightly sprinkle some regular coconut on the top and sides of the cake. Then follow-up with toasted coconut.