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Peanut Butter Brownies with Box Mix


By Butter with a Side of Bread
(Serves 16)

These brownies are an easy take on traditional brownies.  They are fudgy, decadent brownies with an incredible swirl of peanut butter that everyone is surely to love!


  • Regular box of brownie mix
  • 2 large eggs
  • 1/2 cup oil
  • 1/2 cup creamy peanut butter, microwaved about 30 seconds until it is pourable
  • 1/2 cup cold/room temperature coffee (you can also substitute water if you wish)
  • 1/4 cup chopped peanuts.


  1. Heat the oven to 350 degrees.  Spray a 9" x 13" cake pan with cooking spray.
  2. In a large mixing bowl, combine the dry brownie mix with the eggs, oil, and coffee (or water) and stir until combined.
  3. Pour the prepared brownie batter mix into the prepared baking pan.
  4. Put the peanut butter into a small bowl and microwave for 30 seconds to melt it slightly.
  5. Use a spoon to drop dollops of the peanut butter over the top of the brownie batter.  Using a knife, swirl the peanut butter throughout the batter.  Be careful not to overmix the batter or the swirls will blend into the batter.
  6. If desired, sprinkle the top of the brownie batter with peanuts or another nut of your choice
  7. Bake for 20-25 minutes or until a toothpick comes out clean.
  8. Allow the brownies to cool slightly before removing them from the pan. 
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