Heat oven to 350°F. Spray cake pans with cooking spray. Make and bake cake mix as directed on box using water, oil, and eggs and adding Pink paste food color. Cool completely.
Line cookie sheet with waxed paper. Crumble cake into a large bowl. Add frosting and chocolate chips; mix well.
Shape into 32 oblong balls; place on cookie sheet. Freeze until firm.
Remove several cake balls from the freezer at a time. Dip tip of 1 lollipop stick 1/2 inch into melted White candy and insert stick into 1 cake ball no more than halfway. Place in refrigerator.
Once set, Dip each cake ball into melted WHITE candy to cover; tap off excess. Poke opposite end of the stick into Foam Block. Let stand until the coating is completely set.
Re-Dip each cake ball into melted Green candy to cover; tap off excess. Return sticks to Foam Block. Let stand until set.
With Sponge (or paintbrush), line Cake Balls with Corn Syrup then sprinkle Green Sanding Sugar to look like watermelons. Let stand until set.