Preheat oven to 350 degrees. Line an 8x8 square pan with foil and spray lightly with baking spray; set aside.
In a bowl of a stand mixer fitted with the paddle attachment, add the butter and beat on medium speed for one minute. Slowly add the confectioners' sugar, cocoa powder, cayenne pepper and cinnamon. Mix until combined, scraping down the sides of the bowl as needed. Add the heavy cream and mix until light and fluffy, about 2 to 3 minutes. Spread the frosting over the brownies, remove from pan and slice before serving.
*Nutritional information is an estimate. Please consult a doctor or nutritionist for the most accurate nutritional info.