Peanut butter and cream cheese make a creamy and rich frosting. This is great as a frosting or a cake filling and it is easy to spread and pipe from a decorating bag. Make sure the cream cheese and butter are at room temperature before you begin,
Combine the cream cheese, peanut butter and butter in a medium-size mixing bowl. Beat with an electric mixer on medium-high speed for 2 to 3 minutes or until smooth. Stop the mixer once or twice to scrape down the sides of the bowl.
Add the vanilla and salt. Mix on medium speed for 1 minute. Scrape down the sides of the bowl.
Add the powdered sugar and blend on low speed or by hand until the sugar is absorbed.
Increase the speed to medium-high and blend 2 to 3 minutes until smooth. Stop the mixer partway through to scrape down the sides.
If the buttercream is too thick, add up to 2 tablespoons of milk and beat well.
Notes
Let the cream cheese and butter soften up at room temperature before you begin. If they are cold when you start then you will get lumpy frosting.
To soften butter quickly, grate it with a cheese grater.
To soften cream cheese quickly, cut in into small cubes and let it sit at room temperature for 15 minutes. The smaller you cube the cream cheese, the quicker it will soften.
When you add the powdered sugar, stir it in slowly at the beginning and increase the speed gradually. If you start the mixer at high speed then the powdered sugar will fly out of the bowl.