In a medium to large mixing bowl, combine all of the ingredients: cake mix, muffin mix, milk, oil, and eggs
Mix until fully combined
Place cupcake liners in the baking sheet
Fill each cupcake liner 2/3 of the way (they will rise!)
Bake at 350 degrees for about 17 minutes or just before the tops turn brown
Poke the center of a cornbread cupcake with a toothpick and make sure it comes out clean. If it does, your cupcakes are done!
Top cupcakes with cinnamon butter, as desired