Preheat oven to 350 degrees F. Liberally grease a 24-cavity miniature muffin pan with cooking spray and set aside. Meanwhile, in a large bowl, combine the cake mix, egg, oil, and ONE (1) tsp of the cinnamon. Stir until a soft dough has formed.

Using a cookie dough scoop, portion Tablespoon-sized balls of dough among each muffin cup. You should get about 16-18 cups of dough. Gently press on the dough to flatten the dough ball.

Bake for approx. 10-12 minutes or until the tops are light golden brown and the center appears mostly set. Remove the cups from the oven and immediately press an indentation into the center of each cup with the handle of a wooden spoon very gently. Press one miniature cinnamon roll into the center of each cookie cup. The cinnamon roll will be larger than the cookie cup, so that's okay - just nestle it in so it's set in there. Allow the cups to cool in the pans for about 15 minutes or so, then carefully lift out and cool completely on a wire rack.

To make the frosting, in a bowl of a stand mixer, beat together the butter, cream cheese, vanilla and remaining teaspoon of cinnamon until creamy and fluffy. Beat in the powdered sugar, about one cup at a time, until the frosting is light and fluffy.

Pipe the frosting high onto the cooled cookie cups, or at least so the cinnamon roll doesn't show. Garnish with additional cinnamon sugar if you'd like. Serve immediately and store leftovers in the fridge.