adapted from joyofbaking.com
1/2 cup peanut butter
1 tablespoon butter at room temp
1 pinch salt
1/4 teaspoon vanilla extract
3/4 - 1 cup powdered sugar
Place the peanut butter, butter and salt in a microwaveable bowl. Heat for about 1 minute, stirring every 20 seconds until warm and soft, but not hot. Stir in the vanilla extract and powdered sugar and mix until it has reached the consistency of cookie dough, adding more sugar if necessary.
This printable recipe from StartingtoSimmer.blogspot.com