Let's Bake

M&M Peanut Butter Cookie Bars

Yield Makes 12-16 bars 1x
Prep: 30 minutesCook: 30 minutesTotal: 50 minutes

Buttery cookie bars made with peanut butter and stuffed with M&M’s and chocolate chips.


  • 115 grams (1/2 cup or 1 stick) unsalted butter, room temperature
  • 180 grams (1 cup) brown sugar
  • 1 teaspoon vanilla extract
  • 125 grams (1/2 cup) smooth peanut butter*
  • 1 large egg
  • 175 grams (1 and 1/4 cups) plain flour or all purpose flour
  • 1/2 teaspoon baking powder
  • 1/4 teaspoon salt
  • 75 grams (1/2 cup) chocolate chips
  • 150 grams (3/4 cup) M&M’s


  1. Preheat oven to 180 C (350 F) standard / 160 C (320 F) fan-forced. Grease and line an 8-inch square pan with baking or parchment paper.
  2. In a large mixing bowl, beat the butter and sugar with an electric mixer until pale and creamy. Add vanilla and peanut butter and mix briefly to combine.
  3. Add egg and continue to mix until soft and creamy. Sift in flour, baking powder and salt. Gently fold until the dough starts to come together.
  4. Throw in the chocolate chips and M&M’s and fold through. Place all the dough into your prepared tin and press down and spread out as evenly as possible using the back of a spoon or a small spatula.
  5. Place in the oven for 28-30 minutes or until golden brown. Remove from the oven and leave to cool completely in the cake pan before cutting into squares.


Peanut butter: I tested this recipe with processed peanut butter, such as Bega, Jif or Skippy. I recommend it over a natural-style peanut butter that has a more oily texture.

Nutrition Information

Serving Size: 1 bar Calories: 256 Sugar: 20.5 g Sodium: 84.2 mg Fat: 13.6 g Carbohydrates: 31 g Protein: 4.1 g Cholesterol: 28.4 mg
Nutrition information is a guide only.
Author: Jessica HolmesCategory: DessertCuisine: American
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