4Once cakes have cooled, place one of the layers on a serving plate and poke holes in layer but not all the way through the cake. Heat 2 cups of milk in a 2 cup measuring cup in the microwave until hot (around 1 to 2 mins). Slowly pour 1/3 of the hot milk in the holes evenly over the bottom layer. Add some of the cool whip, then some of the coconut on top.
Add the 2nd layer, poke holes and slowly pour 1/3 of the milk in the holes evenly over the 2nd layer. Add some cool whip, then some of the coconut.
Add the 3rd layer. Poke holes in the 3rd layer and slowly pour the remaining milk in the holes evenly over the 3rd layer. By this time the layers will be absorbing the liquid and starting to expand and may have some side cracks. That's ok just be very careful with them and try to keep them from breaking completely.
Crumb coat the entire cake by applying a thin layer of cool whip on the top and sides of the cake with a spatula. This will help hold the cake together and remove all crumbs before putting the final cool whip layer on.
Put the cake in the fridge to firm up for about a hour.
Take the cake out of the fridge and apply the last cool whip coating over the top and sides of the cake (you may not use or need all the cool whip). Pat the remaining coconut on top of the cake and around the sides until completely covered. Refrigerate overnight.
*This is a very moist cake. It needs at least overnight refrigeration in order for the layers not to fall completely apart when cutting.