Add water, egg, and cake mix to a bowl and mix well. It will still be slightly lumpy
Add the apple pie filling to a bowl and chop up the apples to smaller pieces with your spoon
Add 1/4 of the cinnamon sugar crumb mix from the box to the apple pie filling and mix well
Grease a 8 inch round spring pan
Pour half of the cake batter into the pan and spread out evenly
Add the apple pie filling on top of half of the batter in the pan and spread out
Add the remaining cake batter and spread out
Add the cinnamon sugar crumb mix on top and spread out evenly
Put the cake in the oven for 50-55 minutes. Check the center with a toothpick to make sure its completely cooked before pulling up
Let cool before cutting into or adding icing if you are doing so
Video
Notes
You don't have to use just apple filling. Think of anything that pairs well with cinnamon, such as peach would taste great as well
If you want part of the recipe to be homemade make your own apple filling. Here is a great recipe for one at The Crumby Kitchen
Let it completely cool before cutting into it. This is kind of a big deal
You don't have to use a spring pan. You can also use a square 8x8 pan or even make these into muffins
In case there isn't enough sugar for you make a icing to drizzle on top with just some powder sugar and water, but wait until the cake has cooled to add it
Be sure and check the center of the cake before pulling out. The center cooks slower so take a toothpick and stick it down the middle. If the liquid is clear that's just the apple filling. If there is a milky colored liquid that is cake batter and keep cooking.