In a standard 9x12 sheet cake pan, "dump" in 2 or 3 cans of your favorite pie filling or fruit. I like to use cherry pie filling & crushed pineapple in syrup. Sometimes (like on 4th of July, to be patriotic) I also add a can of blueberry pie filling.
Open the box of yellow cake mix and "dump" on top of the fruit mix. I shake the pan to even everything out while dumping ingredients.
Pour the melted butter all over the top until it is mostly covered. The more butter, the crustier the top will be after baking (otherwise, it'll turn out still slightly powdery).
Throw it in the oven and bake until the top is a lovely brown color & it all becomes bubbly (45 min - 1 hour). Bake more or less time depending on your oven and ingredients. You should be able to smell the buttery goodness wafting through your house when it's close to being done.
Enjoy!!! It's great served warm. Ice cream or whipped cream is also a tasty addition.