Preheat the oven to the temperature specified on the cake mix box. Grease and flour two 8-inch cake pans.
In a large mixing bowl, prepare the cake batter according to the instructions on the box, substituting softened butter for the oil. Divide the batter evenly between the prepared cake pans.
Bake the cake layers according to the package instructions. Allow the layers to cool completely.
When completely cool, use a sharp knife to split each layer in half horizontally, creating four thin layers.
In a large mixing bowl, use a wooden spoon to combine the thawed frozen topping, sifted powdered sugar, and sour cream. Mix until smooth and well combined.
Stir in the sweetened shredded coconut until evenly distributed throughout the frosting.
Spread the frosting between each layer and over the top and sides of the cake.
Cover the cake lightly with plastic wrap and refrigerate for four days to allow the flavors to meld together.
Before serving, garnish the cake with your choice of toppings, such as chopped pecans, toasted coconut, or seasonal fruits if desired
