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+ servings

Peanut Butter Blondies with Chocolate Buttercream

Soft peanut butter bars covered with chocolate frosting— they’re incredibly indulgent!


Peanut Butter Blondies:

  • 10 tablespoons unsalted butter (166 grams)
  • 2 cups light or dark brown sugar (425 grams)
  • 1 cup peanut butter (270 grams), smooth or crunchy
  • 2 large eggs
  • 2 teaspoons vanilla extract
  • 1/2 teaspoon salt
  • 2 cups all-purpose flour (240 grams)
  • 1 teaspoon baking powder

Chocolate Buttercream:

  • 6 tablespoons unsalted butter (85 grams), softened to room temperature
  • 1/4 teaspoon salt
  • 2 cups powdered sugar (227 grams), sifted
  • 3-4 tablespoons milk
  • 3/4 cup semi-sweet or bittersweet chocolate chips (128 grams), melted


To make the blondies:

  • Preheat oven to 325°F. Line a 9x13 inch baking pan with parchment paper or grease with nonstick baking spray.
  • Melt the butter and sugar together in a medium saucepan over medium heat. Once melted, remove from heat and allow to cool for 5 minutes. Stir in the peanut butter until combined. Add the eggs one at a time, and then the vanilla, stirring until combined.
  • In a separate bowl, combine the flour, baking powder, and salt. Add to the wet ingredients and stir until combined. Spread the batter into the prepared baking sheet. Bake for 30-40 minutes, until a toothpick inserted into the center comes out mostly clean.
  • Let cool completely before frosting.

To make the buttercream:

  • Combine all ingredients in the bowl of a stand mixer fitted with a paddle attachment. Beat on medium speed until smooth, scraping down the mixer bowl a few times as needed.
  • Frost blondies with buttercream. Slice into squares and serve.
  • To melt chocolate, microwave chocolate in a heat-proof bowl on high in 30 second intervals. Stirring until smooth.


Calories: 318kcal, Carbohydrates: 41g, Protein: 5g, Fat: 16g, Saturated Fat: 7g, Cholesterol: 38mg, Sodium: 137mg, Potassium: 163mg, Fiber: 1g, Sugar: 31g, Vitamin A: 265IU, Calcium: 39mg, Iron: 1mg
Have you tried this recipe?I’d love to hear about it! Leave a review below or take a photo and tag it on Instagram @completelydelicious with #completelydelicious.