Preheat oven and prepare cake pan(s) according to package directions
Mix cake mix and cinnamon in mixing bowl. Add coke, coffee, vegetable oil, and eggs. Stir until combine, then beat on medium speed with electric mixer for two minutes.
Pour batter into prepared pan(s) and bake according to package directions. Meanwhile prepare mocha fudge frosting by combining ingredients with an electric mixer. Let frosting cool until spreading consistency.
When cake and frosting are cool, frost cake and serve.