Beat the butter, vanilla, and salt until creamy.
Mix together the cocoa powder and powdered sugar. Slowly add the powdered sugar and whipping cream to the butter mixture a little at a time while beating. Continue adding until everything is mixed in.
Beat on high for a 3-4 more minutes until the frosting is light and fluffy.
Use a piping bag and icing tip 1M to swirl the frosting on cupcakes or cookies.