Place softened butter and creamy peanut butter in the bowl of a stand mixer fitted with the paddle attachment.

Beat on medium speed for approximately 2 minutes until the mixture is completely smooth and lightened in color.

Reduce mixer speed to low and gradually add the sifted powdered sugar, 1/2 cup at a time, until fully incorporated.

Add the vanilla extract and salt to the mixture.

While mixing on low, slowly add the heavy cream one tablespoon at a time.

Increase the mixer speed to medium-high and whip the frosting for 2 to 3 minutes until it becomes light and fluffy.

Adjust consistency if necessary: add more cream for a thinner frosting or more powdered sugar for a stiffer piping consistency.