Mix cake as directed on package. Let the cake cool on a wire rack when done.
While cake is cooling, mix the Jell-O gelatin with the boiling water in a small bowl. Add 1 cup of soda, then mix well together. Let it get a little thick, and then slowly pour over the top of the cake.
Mix pudding, Cool Whip & milk together & beat for 2 minutes. Spread on cake & serve or put in refrigerator until ready to serve.