1 cup unsalted butter, softened
3 1/2 cups powdered sugar
1/2 cup unsweetened cocoa powder
1/4 teaspoon salt
2 teaspoons vanilla extract
3 to 4 tablespoons milk or heavy cream
Beat the softened butter until smooth and creamy
Add the cocoa powder and salt, then mix until combined
Gradually add the powdered sugar, mixing on low speed
Add the vanilla extract
Add the milk or cream one tablespoon at a time until desired consistency is reached
Beat on high speed for 1 to 2 minutes until light and fluffy