16 ounces pineapple slices (drained, but reserve juice for cake batter)
1 box yellow cake mix (with ingredients on the back of the box, with water switched out for pineapple juice)
3.4 ounces instant vanilla pudding mix
1 ½ cups milk
8 ounces whipped topping
8 ounces pineapple chunks (drained)
Preheat oven to 350 degrees Fahrenheit.
Lightly spray a 9×13 pan with cooking spray and then line the bottom of it with pineapple slices.
Mix together yellow cake mix according to package instructions (swap out the water for pineapple juice for extra flavor!) and pour the batter over the pineapple slices.
Bake the cake according to boxed cake directions, between 25-28 minutes. You will know the cake is done when you touch the center and it bounces back.
Set the cake on a cooling rack and let it cool completely.
Poke 16-20 holes into cake with the end of a wooden spoon.
Mix together pudding and milk, whisking until smooth. Pour this mixture onto the cake and spread out with a knife or spatula, moving it back and forth over the holes in the cake to make sure the pudding sinks down into the holes.
Top with whipped topping and pineapple chunks.
Refrigerate for at least 2 hours before serving. Store leftovers in the refrigerator.