Preheat oven to 350°F. Spray a 9x13-inch pan with cooking spray and line with parchment paper. Set aside.
In a large bowl, use an electric mixer to beat together cake mix and eggs until well combined. Mixture will be thick.
Switch to a spatula and mix in the apple pie filling and applesauce until well combined. Spread into the prepared pan.
In a medium bowl, mix together the brown sugar, flour, apple pie spice, and salt. Work the butter into the mixture with a fork, pastry blender, or your fingertips until large clumps form. Sprinkle over the cake batter.
Bake for 40-45 minutes, or until a toothpick inserted in the center of the cake comes out clean.
Notes
I personally think this coffee cake is sweet enough on its own, but if you would like to add an icing drizzle, feel free to use the icing from my easy peach coffee cake and add it once the cake has cooled.Helpful resources: