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A stack of lunch lady peanut butter bars

Lunch Lady Peanut Butter Bars

  • Author: Erin
  • Total Time: 45 minutes + time for chocolate to set
  • Yield: 18-24 bars, depending on size 1x


Layers of peanut butter oatmeal cookies, even more peanut butter, and chocolate frosting make these bars a rich, delicious treat.



Peanut Butter Oatmeal Cookie Layer:

  • 1/2 cup (1 stick) unsalted butter, softened
  • 1/2 cup white granulated sugar
  • 1/2 cup light brown sugar, packed
  • 1/2 tsp pure vanilla extract
  • 1 large egg
  • 1 1/4 cups creamy peanut butter, divided
  • 1 cup old-fashioned oats
  • 1 cup all-purpose flour
  • 1/2 tsp baking soda
  • 1/2 tsp salt

Chocolate Frosting

  • 1/4 cup (4 TBS) unsalted butter, softened
  • 2 TBS milk, any kind
  • 1 tsp vanilla extract
  • 2 TBS cocoa powder
  • 1 1/2 cups powdered sugar, sifted to prevent lumps


  1. Preheat oven to 350F.  Lightly grease a 9x13 baking pan and set aside.
  2. Using a stand or hand mixer, cream the butter with white and brown sugars for 5-6 minutes.
  3. Add the vanilla, eggs, and 1/2 cup of the peanut butter.  Mix until combined.
  4. Add the oats, baking soda, and salt and mix just until combined - do not overmix.
  5. Spread dough into the prepared baking pan and press into an even layer.
  6. Bake for 15 minutes and remove from oven.
  7. While the cookies are still hot, drop the remaining 3/4 cup of peanut butter over the top and let it sit for a few minutes to get soft and melty.  Spread peanut butter into an even layer.  Allow to cool.
  8. While the pan is cooling, make the chocolate frosting.  Combine the butter, milk, vanilla extract, cocoa powder, and powdered sugar and mix until smooth and not lumpy.
  9. Spread chocolate frosting over the top of the bars and let it sit for an hour or two to set up (the frosting will always be a little soft).
  10. Use a hot knife (run the blade under hot water) to cut into squares.  Store leftovers in an airtight container.


I recommend using natural peanut butter with no added sugars to keep the bars from becoming too sweet (use no-stir varieties or make sure you stir it well)

You can use quick or instant oats if you do not have old-fashioned, but they will be softer in the cookie layer.

You can double this recipe for use in a half sheet pan.

  • Prep Time: 10 mins
  • Cook Time: 15 mins + cooling
  • Category: Dessert
  • Method: Oven

Keywords: lunch lady, school cafeteria, peanut butter cookies, peanut butter bars, oats, chocolate frosting

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