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Perfected Peanut Butter Bars

**Quantities of ingredients for a 9x13 pan are listed first, the ingredient amounts in ( ) are for a standard jelly roll pan 11x18 in size**
Cook Time 20 minutes
Total Time 20 minutes
Servings 24 -48 pieces
Author Si Foster, A Bountiful Kitchen


  • 3/4 cup unsalted butter 1 cup + 2 tablespoons
  • 3/4 cup brown sugar 1 cup + 2 tablespoons
  • 3/4 cup sugar 1 cup + 2 tablespoons
  • 3/4 cup smooth peanut butter 1 cup + 2 tablespoons
  • 2 large eggs 3 eggs
  • 2 teaspoons vanilla 1 tablespoon
  • 1 1/2 cups flour 2 1/4 cups flour
  • 1 1/2 cups old fashion oats 2 1/4 cups oats
  • 1/2 teaspoon salt 1 teaspoon
  • 3/4 teaspoon baking soda 1 teaspoon

for chocolate layer:

  • 2 cups semi sweet chocolate chips 3 cups

for frosting:

  • 1 cup peanut butter 1 1/2 cups
  • 1/4 cup butter softened (6 tablespoons)
  • 2-3 cups powdered sugar 4 1/2 cups
  • dash of salt
  • 2-3 tablespoons milk about 1/4-1/3 cup


  1. Preheat oven to 325 degrees and place rack in center of oven.
  2. Cream butter, sugars and peanut butter until smooth on medium speed.
  3. Add eggs and vanilla and beat until smooth on medium speed.
  4. Turn off mixer and add flour, oats, salt and baking soda to bowl. Pulse mixer or mix on low until ingredients are incorporated. I pulse the ingredients, then use a large silicone spatula to scrape the bottom of the bowl and fold until the ingredients are all mixed together.
  5. Bake for 18-20 minutes for 9x13 or about 20-25 minutes for 11x18 jelly roll pan.
  6. Remove from oven and turn heat off. Sprinkle chocolate chips onto top of cookie layer.
  7. Return to oven for 2 minutes. Remove pan again and using a knife or offset spatula, spread melted chocolate chips evenly over cookie layer.
  8. Let cool completely on counter, or place in fridge to speed up cooling process (see recipe notes).
  9. Make peanut butter frosting by creaming softened butter and peanut butter together in a large bowl. Add powdered sugar, dash of salt and milk until light and fluffy. Spread on top of cooled chocolate mixture.
  10. Cut into pieces and serve.

Recipe Notes

-Do not use "Natural" peanut butter. Natural peanut butter is too soft and runny and will not work in this recipe. I suggest Skippy or Jif brands. Smooth is best. If you use chunky, the frosting will not turn out smooth. -I speed up the cooling process by refrigerating an additional jelly roll pan before starting recipe. When the pan of cookies is ready to set up, after melting chocolate chips on top. I place the pan on top of the cooled pan in refrigerator and let cool inside of the refrigerator. This usually takes about 15-20 minutes.