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+ servings
stack of peanut butter cookie bars with one bar in front of the stack

Peanut Butter Cookie Bars

Thick, chewy, and peanut buttery, these peanut butter cookie bars are pb-lover's dream!

Course Dessert
Cuisine American
Prep Time 15 minutes
Cook Time 20 minutes
Total Time 35 minutes
Servings 16
Author Kelsie


  • 1/2 cup creamy peanut butter don’t use natural
  • 1/2 cup unsalted butter at room temperature*
  • 1 cup packed light brown sugar
  • 1 large egg
  • 2 tablespoons whole milk
  • 1 teaspoon vanilla
  • 1/4 teaspoon baking soda
  • 1/4 teaspoon salt
  • 1 1/2 cups all-purpose flour
  • 1 cup chopped peanut butter cups** optional


  1. Preheat the oven to 350 degrees. Spray a 9-inch square baking pan with cooking spray. Line with foil, allowing several inches of excess to hang over the sides. Spray the foil with cooking spray and set pan aside.
  2. Cream the peanut butter, butter, and sugar together in a large mixing bowl with an electric mixer until light and fluffy. Beat in the egg, milk, vanilla, baking soda, and salt.
  3. Turn mixer to low and beat into the flour until just combined. Fold in the peanut butter cups with a rubber spatula
  4. Press into an even layer in the prepared pan and bake 20 to 25 minutes, until puffed and golden around the edges.
  5. Remove from the oven set pan on a wire rack to cool room temperature. Once the bars have cooled, use the foil to remove the bars from the pan, then slice and serve.
  6. Uneaten cookie bars can be stored in an airtight container at room temp for up to 2 days or in the freezer for up to 3 months.

Recipe Notes

  • *If your butter is cold, cut it into small chunks and it will come up to room temperature much faster. You’ll know the butter is ready to use when you can press it with your fingertip and it gives a bit but still holds its shape.
  • **If you don’t want to use peanut butter cups you can substitute chocolate chips, roasted salted peanuts, coarsely chopped banana chips, or whatever mix-ins you like.