1 cup unsalted butter, room temperature
1 heaping cup creamy peanut butter (I use JIF)
3 cups powdered sugar
1/2 cup heavy cream
pinch of salt

Instructions

In the bowl of your stand mixer, cream together the peanut butter and butter for 2-3 minutes. You want the color to lighten by a few shades.
Add the powdered sugar, scrape the sides of the bowl and mix until combined.
Pour in the heavy cream and beat until smooth. Scrape the bowl again.
Mix in the salt.
Beat on high for 3-4 minutes or until the buttercream has become light and fluffy.
Use immediately.