Start with your preferred brand of yellow cake mix.
Skip the vegetable oil and water typically called for in the instructions.
Add three to four eggs, a packet of pistachio pudding, and a cup of Sprite or your choice of lemon-lime soda.
Mix everything together and pour the batter into a greased baking pan.
Bake at 350 degrees Fahrenheit for about 30 to 40 minutes.
For frosting, mix another packet of pistachio pudding with room temperature butter, confectioners' sugar, and cold milk.
Consider adding canned crushed pineapple or finely chopped pecans to the cake mix.
Frost the cake and dot it with halved maraschino cherries or miniature marshmallows.
