Grease or spray two 8- or 9-inch round cake pans. In a small bowl, toss 1/2 cup of the chocolate chips with 1 Tbsp. of the cake mix. In a large bowl, beat remaining cake mix, the water, oil, egg whites and drink mix with electric mixer on low speed 30 seconds, then on medium speed 2 minutes, scraping bowl occasionally. Stir in the 1/2 cup chocolate chips. Pour into pans.
Bake in a preheated 350º oven as directed on cake mix box for 8- or 9-inch rounds. Cool as directed.
In a small bowl, stir 1 cup of the frosting with 10 to 12 drops green food color. Stir 10 to 12 drops red food color into remaining frosting. Frost sides of cakes with green frosting; press green jelly beans into frosting. Frost tops of cakes with red frosting; press remaining 2 Tbsp. chocolate chips into frosting for seeds. If desired, cut cakes crosswise in half and arrange "slices" randomly on tray. To serve, cut into wedges. Store loosely covered.