Lunch Lady Peanut Butter Bars

These Lunch Lady Peanut Butter Bars are exactly like you remember from school!

With a chewy peanut butter oat base, creamy peanut butter center, and rich chocolate buttercream topping, these cafeteria-style peanut butter chocolate bars are the best, and so simple to bake.

I don’t really know what kind of desserts they serve in school nowadays, but back in the day, the school cafeteria was known for having the best desserts!

Lunch Lady Brownies, Lunch Lady Peanut Butter Cookies, and these Chocolate Peanut Butter Bars all get their name from the wonderful people who used to bake them for us.

Those ladies really knew what they were doing!

If you’re a big fan of chocolate and peanut butter together, you’re in luck! I have plenty of other sweet treats for you to make.

My Chocolate Peanut Butter Oatmeal Bars are a no-bake recipe that comes together quickly and easily.

There’s also Buckeye Brownie Cookies, Peanut Butter Pie, and snackable Peanut Butter Pretzel Bites.

Why You’ll Love This Recipe

1. Simple Ingredients – Lunch lady peanut butter bars are made with pantry staples, most of which you might already have on hand! I love recipes like this because I can whip up a batch whenever the mood strikes.
2. Enough for a Crowd – Like most brownies and bar cookies, this bar recipe makes a large pan of peanut butter squares. Cut them into 24 generous pieces to share.
3. They’re So Delicious! – I had to use a lot of self-restraint to keep from eating half the pan! The peanut butter cookie base is perfectly soft and chewy, and the rich chocolate buttercream frosting is just divine!

Key Ingredients

Here’s what you need to make the best Lunch Lady Peanut Butter Bars:

• Rolled Oats: The cookie base for these bars includes old-fashioned oats. Oats give the bars a chewy, wholesome texture.
• Peanut Butter: Choose traditional smooth peanut butter for this recipe, rather than all-natural versions.
• Brown Sugar: Both granulated sugar and brown sugar go into the cookie recipe. Brown sugar helps to keep the bars moist and chewy, while regular sugar allows the outside edges to get crispy.
• Butter: Choose unsalted butter for baking. You’ll need melted butter for the base and softened butter for the frosting.
• Cocoa Powder: To make a simple and delicious chocolatey buttercream.

Complete list of ingredients and amounts can be found in the recipe card below.

How To Make Lunch Lady Peanut Butter Bars

Start by preheating the oven to 350°F (180°C). Grease a 9×13-inch baking pan and set it aside.

1. Mix the Wet Ingredients: To make the oatmeal cookie base, start by mixing together the melted butter, 1 cup of peanut butter, granulated sugar, brown sugar, salt, vanilla, and eggs until well combined.
2. Add the Dry Ingredients: Add the flour and oats to the mixture.
3. Fold: Fold in the oats and flour until you have a smooth cookie dough.
4. Press: Use your hands to press the dough evenly into a greased 9×13-inch baking pan.

5. Bake: Bake in the preheated oven for 15-20 minutes, or until lightly browned. Let the base cool completely before continuing.
6. Add Peanut Butter Filling: Melt 1.5 cups of creamy peanut butter in the microwave at 20-second intervals, stirring after each. You can also use a double boiler on the stovetop if you prefer. Pour the melted peanut butter all over the cookie base. Refrigerate while you make the frosting to set the peanut butter layer.

7. Make the Frosting: In a medium saucepan, melt the ¼ cup butter over low heat. Add the milk and cocoa powder, whisking until smooth. Remove the chocolate mixture from the heat. Gradually stir in the powdered sugar, one cup at a time. Then mix in the vanilla extract.
8. Frost: Spread the frosting over the set peanut butter layer. Refrigerate the bars for at least an hour to set the frosting, then cut into squares to serve.

Recipe Tips

• Choose the right oats: Quick or instant oats don’t have the right texture for this recipe. Be sure to use old-fashioned rolled oats for the best result.
• Pay attention to the chilling steps: You want the base to be mostly cooled before adding the peanut butter, and you want the peanut butter to be set before adding the frosting. Before cutting into the bars, give them at least an hour in the fridge to set and cool fully.
• Starting the frosting on the stove actually helps to bloom the cocoa powder, which makes the frosting extra rich and decadent. If you don’t want to do it that way, try my classic chocolate buttercream recipe instead.
• Try some toppings! Cover the top of these peanut butter chocolate bars with chopped Reese’s cups, chocolate chips, or sprinkles to make them extra tasty and festive.

Storing Tips

Keep your frosted peanut butter bars in an airtight container. They’ll stay at room temperature for up to 5 days.

You can also store these in the fridge for the same amount of time. They’re actually very delicious when served chilled!

Freeze individual lunch lady peanut butter bars for up to 3 months. I suggest freezing them first on a baking tray, then wrapping each bar well with plastic wrap and adding them to a freezer bag. This way they won’t stick together.

Recipe FAQs

Just like you remember, these Lunch Lady Peanut Butter Bars are amazingly tasty! And even if you never at a peanut butter bar at school, you’ll be glad that you found this easy recipe.