Heat oven to 350°F Grease bottoms only of two 8- or 9-inch round pans with shortening or cooking spray.
In large bowl, stir into batter 1/2 cup of the chocolate chips. Add the drink mix, stir, and pour into pans.
Bake 27 to 32 minutes or until toothpick inserted in center comes out clean. Cool 10 minutes; remove from pans to wire racks. Cool completely, about 1 hour.
In small bowl, stir 1 cup frosting with 10 to 12 drops green food coloring. Stir 10 to 12 drops red food color into remaining frosting.
Cut cake rounds crosswise in half to make 4 halves. Frost uncut sides with green frosting; press green jelly beans into frosting. Frost top of cake with red frosting; press remaining 2 tablespoons chocolate chips into frosting for seeds.