Two possibilities
Peanut Butter Butter Cream Frosting
8 tablespoons unsalted butter , softened
1/2 cup smooth peanut butter , don’t use old-fashioned or natural brand
3/4 cup confectioners’ sugar
1 pinch table salt
1/2 teaspoon vanilla extract
1 tablespoon heavy cream
In standing mixer fitted with whisk attachment, beat butter and peanut butter at medium-high speed until smooth, about 20 seconds. Add confectioners’ sugar and salt; beat at medium-low speed until most of the sugar is moistened, about 45 seconds. Scrape down bowl and beat at medium speed until mixture is fully combined, about 15 seconds; scrape bowl, add vanilla and heavy cream, and beat at medium speed until incorporated, about 10 seconds, then increase speed to medium-high and beat until light and fluffy, about 4 minutes, scraping down bowl once or twice.
1/2 cup butter (softened)
1 cup creamy peanut butter
2 cups powdered sugar (sifted)
1/4 cups + 1 to 2 tbs heavy cream
Cream together the butter and peanut butter. Then add the powdered sugar & 1/4 cup of the heavy whipping cream. Add 1 to 2 tablespoons as needed til you have the consistency that you’re wanting.
These look very good, too—thank you! Are you a food scientist or is cooking an avocation?