In a large bowl, tear angel cake to small pieces and set aside. In another bowl dissolve Jello in 1 cup of hot water then pour in the soda. Pour over angel cake and fold in carefully. Pour complete mixture in 13 x 9 inch pan. Let stand in refrigerator for a few hours. Dissolve pudding in cold milk and let come to pudding stage. Fold in Cool Whip. Pour over cake.