In a stand mixer with the beater blade, beat the butter for 1-2 minutes until it is smooth, creamy and nearly white in appearance.
Add in the salt and vanilla. Mix until incorporated.
With the mixer on low speed, slowly add in the powdered sugar and cocoa powder.
Add the heavy cream, a tablespoon at a time, mixing slowly until it is the consistency that you'd like.
Beat for 1 minute on medium speed until smooth and creamy.
We like to use the beater blade attachment. If you'd like an airier frosting, you can use the whisk and beat the frosting for an additional 1-2 minutes. This will whip more air into the frosting, which makes it delicious, but it will also not spread on as smoothly.We used regular cocoa powder, but if you'd like deeper, darker flavor, use special dark cocoa powder.The calories shown are based on 1/15 of the frosting. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate.