1-Preheat the oven: Preheat oven to 350°F (175°C). Grease two 9-inch round cake pans with butter or spray, dust with flour, and line bottoms with parchment.

2-Combine dry ingredients: In a large bowl, whisk together flour, sugar, cocoa powder, baking powder, baking soda, cinnamon, cayenne pepper, and salt until uniform.

3-Mix wet ingredients: In a separate bowl, whisk buttermilk, vegetable oil, eggs, vanilla extract, and hot coffee until fully blended; the mixture will be thin.

4-Combine mixtures: Slowly pour wet mixture into dry ingredients. Gently stir with a spatula just until no flour streaks remain. Do not overmix; batter will be slightly bubbly.

5-Bake the cake: Divide batter evenly between prepared pans, tap on counter to release air pockets. Bake for about 35 minutes, until a toothpick inserted in center comes out with moist crumbs.

6-Let cool: Cool cakes in pans on a wire rack for 10 minutes. Run a knife around edges, invert onto rack, remove parchment, and cool completely before frosting.

7-Prepare frosting: Beat room temperature butter until creamy and pale, about 2 minutes. Mix in vanilla and cinnamon. Gradually add powdered sugar on low speed, then drizzle heavy cream until frosting is fluffy and spreadable.

8-Assemble & frost: Place one cooled cake layer flat side down on a plate. Spread about 1 cup frosting on top. Top with second layer flat side down. Frost top and sides with remaining frosting. Sprinkle with mini chocolate chips.