Prepare cake batter and bake as directed on package for 13x9-inch pan. Cool cake in pan 15 min. Using a large fork or end of wooden spoon, pierce cake at ½-inch intervals.
Using a medium bowl, add Coca-Cola and water to gelatin and mix; stir 2 min. until dissolved. Pour over cake. Refrigerate ½ hour.
Combine vanilla pudding mix with milk and vanilla. Mix until smooth. Gently fold in whipped topping then spread evenly over cake.
Refrigerate at least 3 hours or overnight. Garnish with chocolate jimmies and cherries when serving.
