First, prepare your cake: Preheat oven to 350 degrees F. and liberally grease a 13x9" baking pan with cooking spray; set pan aside. Prepare your cake mix according to package directions. Stir in the espresso powder and the cinnamon to combine.
Pour the cake batter into the prepared pan and bake for approx. 20-23 minutes or until a toothpick inserted near the center comes out clean or with moist crumbs. Cool the cake completely. Once cake has cooled, poke holes in it using the handle of a wooden spoon, careful not to completely penetrate the cake all the way through.
In a small bowl, whisk together the yogurt, condensed milk and Kahlua until blended. Pour the mixture evenly over the top of the cake, careful to fill the holes as best as you can. Allow the cake to sit in the fridge for about 20 minutes, then spread the Cool Whip on top in an even layer.
Refrigerate the cake for about 4 hours, or overnight, to settle and allow the flavors to combine and absorb into the cake. Cut into squares and serve! Store leftovers covered in the fridge for about 3 days.