1 -2 cups of blueberries and strawberries, or your favorite combination of berries to arrange on top
To make the frosting, combine all of the frosting ingredients and mix with a hand mixer until fluffy.
Slice off the top, bottom, and sides of the watermelon and "trim" so that it resembles the shape of a cake.
Pat the top dry with a paper towel and decorate with frosting and your favorite assortment of berries. To make the little stars- use a small cookie cutter to cut into semi thin slices of watermelon. These stars act as awesome decoration.
Store in the fridge- cover once the frosting has gotten hard.