Spice, white, and carrot cake mix would make great substitutions for the yellow cake mix.
Of course, this is meant to be an apple version of dump cake, but you can always play around with variations by using cherry pie filling, blueberry or peach.
Place any leftover dump cake in an airtight container. You can store it in the fridge or keep it out on the countertop. It tastes good chilled, at room temperature, or warmed up.