yellow cake mix, any type
(1-oz.) fat-free, sugar-free, instant pudding
whipped topping, fat-free
Preheat oven according to package directions for cake mix.
Use cooking spray to grease a 9" x 13" cake pan.
In a large bowl, combine cake mix and Diet Coke; mix until smooth.
Pour into prepared pan and bake according to directions on box.
When cake is cool, cut into 1-inch cubes (cake will crumble).
Prepare pudding mix with milk as directed on package.
In a large glass bowl, layer a third of the cake cubes, a third of the pudding, and then a third of the whipped topping.
Repeat twice, using all ingredients.
Refrigerate for at least 1 hour and serve chilled.