Peanut Butter Bars


Peanut Butter Bars are one of the best treats! You get a chewy oat cookie base that’s loaded with peanut buttery flavor, then it’s topped with a layer of peanut butter after baking and finished with a decadent chocolate frosting. Trust me this is a staple recipe!

Stack of peanut butter bars. They have a layer of peanut butter oatmeal cookie dough, layer of cream peanut butter then a layer of chocolate frosting.

A Long Time Family Favorite!

These are one of my favorite childhood treats. My mom and everyone else I know always made them.

They are perfect for parties because they make a full cookie sheet, and adults and children alike absolutely love them.

I mean, who doesn’t love the chocolate and peanut butter combo, and who doesn’t love cookie bars and frosting?

I made them yesterday and it’s one of those things where I kept going back and cutting off a thin slice, then another, then another and then I woke up for breakfast at it was the first thing I just had to have a taste of.

They really are one of the most tempting desserts you’ll ever make! Try them and you’ll see what I mean.

Peanut butter cookie dough in mixing bowl for peanut butter bars.

Ingredients for Peanut Butter Bars

  • All-purpose flour – for structure
  • Quick oats – for texture
  • Baking soda – so the bars rise
  • Brown sugar, granulated sugar and powdered sugar – to sweeten
  • Salt – to balance the sweetness
  • Unsalted butter – to moisten and add richness
  • Eggs – to bind
  • Creamy peanut butter – to add flavor
  • Vanilla – to add another light layer of flavor
  • Cocoa powder – to add chocolate flavor to the frosting
  • Milk – to thin the frosting

How to Make Peanut Butter Bars

Even though they do have several layers these really are a breeze to make.

  • Preheat oven and butter a rimmed baking sheet.
  • Whisk together dry ingredients.
  • In an electric mixer cream together butter, brown sugar and granulated sugar
  • Mix in eggs one a time then blend in peanut butter and vanilla.
  • Mix in dry ingredients.

Spreading peanut butter cookie dough into a baking sheet.

  • Spread mixture onto baking sheet.
  • Bake until nearly set.

Spreading peanut butter over warm peanut butter bars.

  • Cool briefly then dollop over peanut butter, let peanut butter melt then spread.
  • Prepare and pour over chocolate frosting then spread into an even layer and let set.

Pouring chocolate frosting over peanut butter bars.

Tips for this Recipe

  • Don’t use crunchy peanut butter or it will through the recipe off.
  • Add peanut butter while cookies are still warm so it melts nicely and sort of absorbs into the cookies a little.
  • Be careful not to over-bake these or the edges will be dry. Plus they’ll continue to cook just a little once removed from the oven from the heat of the baking sheet.

Peanut Butter Bars

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Peanut Butter Bars with Chocolate Frosting

4.5 from 2 votes

Peanut Butter Bars are one of the best treats and they're great for parties because they make enough for a crowd! You get a chewy oat cookie base that's loaded with peanut buttery flavor, then it's topped with a layer of peanut butter after baking and finished with a decadent chocolate frosting.

Servings: 30
Prep Time 30 minutes
Cook Time 12 minutes
Total Time 42 minutes


  • 2 cups (283g) all-purpose flour
  • 2 cups (181g) quick oats
  • 1 tsp baking soda
  • 1/2 tsp salt
  • 1 cup (226g) unsalted butter, softened
  • 1 1/4 cups (260g) packed light-brown sugar
  • 3/4 cup (150g) granulated sugar
  • 2 large eggs
  • 1 cup (243g) creamy peanut butter
  • 1 tsp vanilla extract


  • 1 cup (243g) creamy peanut butter
  • 1/2 cup 113g) unsalted butter, diced into 1 Tbsp pieces
  • 1/4 cup (26g) unsweetened cocoa powder
  • 1/4 cup (60g) milk
  • 2 pinches salt
  • 1 tsp vanilla extract
  • 3 cups (360g) powdered sugar


  1. Preheat oven to 350 degrees. Butter a rimmed 18 by 13-inch cookie sheet.

  2.  In a mixing bowl whisk together flour, oats, baking soda and salt. Set aside.
  3. In the bowl of an electric stand mixer fitted with the paddle attachment, blend together butter, brown sugar and granulated sugar until creamy. 
  4. Mix in eggs one at a time. Blend in 1 cup peanut butter and the vanilla. With mixer set on low speed, slowly add in flour mixture and mix just until combined.
  5. Drop cookie dough onto prepared baking sheet. Spray hands with non-stick cooking spray and spread dough into an even layer. 
  6. Bake in preheated oven 12 - 15 minutes until golden (see notes).

  7. Remove from oven and cool 5 minutes, then dollop remaining 1 cup peanut butter by spoonfuls over top. Let sit 1 minute then spread peanut butter into an even layer to cover top.
  8. Melt butter in a medium saucepan. Stir in cocoa, milk and salt and bring mixture just to a boil over medium heat. 
  9. Remove from heat and whisk in vanilla, then stir in powdered sugar and mix until well combined (if needed you can add 1 Tbsp hot water to thin). 
  10. Immediately pour over bars and spread into an even layer. Allow frosting to set then cut into squares. Store in an airtight container.

Recipe Notes

  • Be careful not to over-bake or edges will be dry, don't wait for it to be golden brown. They should be puffed and beginning to set but still soft.
  • Recipe adapted from Taste of Home
Nutrition Facts
Peanut Butter Bars with Chocolate Frosting
Amount Per Serving
Calories 339 Calories from Fat 162
% Daily Value*
Total Fat 18g 28%
Saturated Fat 7g 35%
Cholesterol 35mg 12%
Sodium 190mg 8%
Potassium 170mg 5%
Total Carbohydrates 40g 13%
Dietary Fiber 2g 8%
Sugars 26g
Protein 6g 12%
Vitamin A 6%
Calcium 2.6%
Iron 7%
* Percent Daily Values are based on a 2000 calorie diet.
Course: Dessert
Cuisine: American
Keyword: Peanut Butter Bars
Calories: 339 kcal
Author: Jaclyn


  • Debi: These used to be called Lunch Lady Peanut Butter Bars. I remember having these in high school in 1980 at lunch. I have made these with crunchy peanut butter and they turned out fine. I like the added crunch of the peanuts. I actually prefer them with crunchy. May 10, 2019 at 8:13pm Reply

  • Dana: Thank you for your speedy reply. 😊 March 17, 2019 at 10:20am Reply

  • Dana Hodge: Do you put peanut butter in the frosting as listed in the recipe? March 16, 2019 at 3:22pm Reply

    • Jaclyn: Sorry for the confusion the peanut butter is added in a layer just underneath the frosting. March 16, 2019 at 11:21pm Reply

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