Preheat the oven to 350°F and prepare an 8x4-inch loaf pan with baking spray, wipe out any excess spray.
In a small bowl, mix together the cinnamon and granulated sugar.
Dust the inside of the greased loaf pan with 1 tablespoon of the cinnamon-sugar mixture.
In a mixing bowl, combine the cake mix, applesauce, and eggs with a wooden spoon until well blended.
Spread 2 cups of the batter in the loaf pan. Top evenly with the remaining cinnamon-sugar mixture. Take 1 cup of the remaining cake batter and spread it evenly over the cinnamon-sugar. You will have about ½ cup of leftover batter, this is the perfect amount for one extra muffin!
Bake for 45 minutes, or until a toothpick inserted in the middle of the cake comes out clean.
Cool the cake in the pan for 15 minutes.
Transfer the cake to a wire rack and let cool completely before serving.