Beat all cake ingredients well by hand. Bake at 350F in either one sheet pan, or 3 layer pans that have been greased and floured. Follow cooking time on cake mix package. Allow cake to cool completely, then turn out onto serving plate.
Dissolve pudding mix powder into crushed pineapple and juice. Add Cool Whip and mix well. Frost cooled cake. Chill before serving. Cake must be kept in fridge.