Ingredients:

  • 1/2 cup (115 g) unsalted butter, softened to room temperature
  • 1/2 cup (128 g) creamy no-stir peanut butter
  • 2 cups (240 g) powdered sugar, sifted
  • 2 Tbsp (30 ml) whole milk, plus more as needed
  • 1 tsp (5 ml) pure vanilla extract
  • 1/8 tsp (0.6 g) fine salt

Instructions:

  1. Leave the butter out for 30 to 45 minutes until it dents easily when pressed.
  2. Pass the powdered sugar through a fine-mesh sieve into a bowl to remove lumps.
  3. Beat the softened butter and peanut butter on medium speed for 2 to 3 minutes until pale, smooth, and fluffy.
  4. Scrape down the sides of the bowl with a rubber spatula so everything blends evenly.
  5. On low speed, add the sifted powdered sugar in 1/2-cup portions, beating until each addition is absorbed before adding the next.
  6. Mix in the vanilla, fine salt, and milk, then beat on medium speed for 1 to 2 minutes until fluffy.
  7. If the frosting is too stiff to spread, add more milk 1 teaspoon at a time until it is glossy and holds a soft peak.
  8. Frost cupcakes, cake, or brownies right away, or store the frosting in an airtight container in the refrigerator for up to 1 week. Let it sit at room temperature for 30 to 60 minutes, then re-whip on medium speed for about 1 minute before using.