Mix together the cake mix, butter, and eggs, and pat in a jelly roll pan. It won’t look like it’ll all reach, but it will. Keep working it.
Bake for 12-13 minutes. This layer will not be done after baking.
Middle Layer
Remove from oven and sprinkle a layer of miniature marshmallows (the whole bag) and bake at 350 degrees for 8 minutes. Marshmallows should be a very light brown.
Remove from oven and allow to cool before adding topping.
Topping
On the stove, heat all topping ingredients (corn syrup, butter, peanut butter chips, vanilla, and creamy peanut butter)until melted. Do not over cook.