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Peanut Butter Smores Oatmeal Cookie Bars

Reese's Peanut Butter S'mores Oatmeal Cookie Bars - total indulgence in each bite!
Course Dessert
Cuisine American
Keyword peanut butter s'mores oatmeal cookie bars
Prep Time 15 minutes
Cook Time 25 minutes
Chill Time 30 minutes
Servings 24 bars
Calories 328kcal
Author Trish - Mom On Timeout


  • 12 tbsp sticks melted
  • 2 cups light brown sugar
  • 1/2 cup creamy peanut butter
  • 2 eggs room temperature
  • 1 tbsp vanilla
  • 1 1/2 cups all-purpose flour
  • 3/4 cup graham cracker crumbs
  • 1 cup old fashioned oats
  • 1 tbsp cornstarch
  • 2 1/2 tsp baking powder
  • 1/2 tsp salt
  • 1 cup Reese's peanut butter baking chips
  • 7 full-size Hershey's chocolate bars
  • 7 oz jar marshmallow fluff
  • 1 cup chopped Reese's miniatures


  • Preheat oven to 350 degrees.
  • Line a 9x13 inch baking dish with parchment paper.
  • Cream butter and sugar together in a large mixing bowl. Add peanut butter and continue mixing.
  • Add eggs one at a time, mixing well after each egg. Add in vanilla.
  • Combine flour, graham cracker crumbs, oats, cornstarch, baking powder, and salt in a small mixing bowl.
  • Add the flour mixture to the butter mixture, slowly stirring until well combined.
  • Stir in the peanut butter chips.
  • Refrigerate cookie dough for at least 30 minutes.
  • Spread 2/3 of the dough on the bottom of the pan.
  • Top with Hershey's bars, breaking apart as needed.
  • Spread marshmallow fluff on top of Hershey's bars.
  • Stir chopped Reese's into remaining cookie dough.
  • Drop the remaining dough on top by the teaspoon. It doesn't have to be perfect and it won't cover all the marshmallow fluff.
  • Bake for 25-30 minutes. Let cool completely and then cut into bars.


Calories: 328kcal | Carbohydrates: 52g | Protein: 6g | Fat: 12g | Saturated Fat: 5g | Cholesterol: 16mg | Sodium: 163mg | Potassium: 217mg | Fiber: 2g | Sugar: 37g | Vitamin A: 44IU | Vitamin C: 1mg | Calcium: 60mg | Iron: 1mg