Go Back Email Link
+ servings

FOLLOW ALONG! Subscribe to my newsletter and follow along on Facebook, Pinterest and Instagram for the latest updates, recipes and content.


Lunch Lady Peanut Butter Bars

These Lunch Lady Peanut Butter Bars are one for the books! A soft, chewy peanut butter oatmeal cookie base is topped with warm and creamy peanut butter and finished off with a sweet chocolate frosting.
Course Dessert, treat
Cuisine American, Vegetarian
Keyword lunch lady peanut butter bars
Prep Time 20 minutes
Cook Time 20 minutes
Total Time 40 minutes
Servings 36 bars
Calories 329kcal
Author Chelsea Lords
Cost $7.12


  • 17x12.25-inch sheet pan with sides
  • Optional: parchment paper


  • 1 cup unsalted butter, softened (this is 16 tablespoons or two sticks)
  • 3/4 cup white sugar
  • 1-1/4 cup brown sugar, tightly packed
  • 2 large eggs
  • 1-1/2 teaspoon vanilla extract
  • 1 teaspoon baking soda
  • 1 teaspoon salt
  • 2 cups old-fashioned oats (Note 1)
  • 1 cup creamy peanut butter (Note 2)
  • 2 cups white, all-purpose flour

Peanut Butter Filling & Frosting

  • 1-1/2 cup creamy peanut butter
  • 1/2 cup unsalted butter, softened (this is 8 tablespoons or 1 stick)
  • 1/4 cup whole milk
  • 1-1/2 teaspoons vanilla extract
  • 1/8 teaspoon salt
  • 1/4 cup cocoa powder
  • 3 cups powdered sugar


  • PREP: Preheat oven to 350 degrees F. Generously grease or add parchment paper to a 17x12.25-inch jelly roll pan (Note 3). Set aside.
  • COOKIE BASE: In a bowl attached to a stand mixer (or use a large bowl with a hand mixer), cream together the softened butter (Note 4), white sugar, and brown sugar until smooth and creamy (the consistency of peanut butter). Add eggs; beat to combine. Add vanilla, baking soda, salt, and oats. Mix until just incorporated and then add in peanut butter. Mix until just incorporated. Finally, add in the flour and mix until just incorporated.
  • BAKE: Spread out dough in an even layer on the prepared sheet pan. Bake for 15-17 minutes and then remove. Be careful to not overbake the bars. We want a soft, chewy, and flavorful cookie base!
  • PEANUT BUTTER: Let cookie bars cool for 5 minutes then warm 1-1/2 cups peanut butter in the microwave for about 30-60 seconds or until it will drizzle nicely. Drizzle the peanut butter evenly on the cookie base and then, using a table knife or offset spatula, gently smooth peanut butter in an even layer. Then let the bars cool completely until the peanut butter has fully set up. (I pop the bars in the fridge/freezer for a little!)
  • FROSTING: Meanwhile, whip together the frosting. Add all the frosting ingredients to a large bowl (or a stand mixer) and beat until smooth and combined. Dollop scoops of frosting on top of bars and gently spread into an even layer.
  • CUT BARS: Cut into the bars with a hot sharp knife. Run the knife under hot water, dry it off, and then immediately cut the bars. Enjoy!
  • STORAGE: Cover leftover bars tightly and store at room temperature for up to 5-7 days. To freeze: Wrap each bar individually in plastic wrap and then store the wrapped bars in a large plastic bag or freezer-safe container. Freeze for up to 3 months. Thaw bars overnight in the fridge.



Note 1: Old-fashioned oats: While it may seem like old-fashioned oats and quick oats can be interchanged easily enough, they don’t work the same when baking. Because of their small size, quick oats act more like flour, absorbing more liquid which results in drier, less-flavorful bars. This recipe relies on old-fashioned oats, and won’t work the same with any other oat type.
Note 2: Peanut butter: Make sure to use creamy, not crunchy, peanut butter for best results. We love and highly recommend Skippy® Creamy Peanut Butter (not sponsored), We don't recommend a natural peanut butter that needs stirring.
Note 3: Pan size: These bars require a specific-sized pan to work and unfortunately, the bars won't turn out well in different sized pans; this part of the recipe is very specific. We are looking for a 17 x 12.25-inch jelly roll pan.
Note 4: What is the consistency of softened butter? The butter should be soft enough to leave a finger indent when using a little bit of pressure, but not soft enough to squish or crush the packaging


Serving: 1serving | Calories: 329kcal | Carbohydrates: 39g | Protein: 6.5g | Fat: 17.3g | Cholesterol: 30.7mg | Sodium: 91.9mg | Fiber: 1.9g | Sugar: 22.7g