In a stand mixer bowl, whip the softened butter on medium speed until it is almost white in appearance.
Add the powdered sugar and cocoa powder. Mix on low speed.
Add in the hot coffee and whip the buttercream on medium speed for 3-4 minutes, or until light and fluffy.
This recipe makes about 2 cups of frosting.
The calories shown are based 1/4 cup of frosting. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**