1 (2 layer size) package white cake mix
1 (4 serving size) package pistachio pudding mix (not instant)
1 cup club soda or 7-Up
1 cup oil
Beat together all ingredients. Pour into greased and floured 9 by 13 inch pan. Bake at 350 degrees for 40 minutes. Cool.
1 (4 serving size) package instant pistachio pudding mix
1 1/4 cups milk
1 (8 ounce) tub frozen whipped topping, thawed
Mix together pudding and milk; add whipped topping. Spread on top of cooled cake. Refrigerate for 4 hours, or overnight before serving.