Peanut Butter Lunch Lady Bars

Peanut Butter Lunch Lady Cookie Bars (Classic Cafeteria Favorite)

A sweet throwback that never goes out of style.

There’s a reason school cafeteria desserts live rent-free in our memories. They were simple, satisfying, and made to feed a crowd—and these Peanut Butter Lunch Lady Cookie Bars are no exception.

Inspired by the classic lunchroom treat we all secretly loved, this homemade version delivers everything you remember: soft, rich peanut butter bars with a fudgy, brownie-like texture and a warm, silky peanut butter frosting poured right on top.

No scooping. No chilling. No rolling dough. Just spread the batter in a sheet pan, bake, and frost. Easy, nostalgic, and dangerously good.

And that frosting? It’s poured on warm so it gently settles into the bars, creating a smooth, creamy finish that sets beautifully. These never last long—especially if you’re sharing.

Why You’ll Love These Peanut Butter Bars

One pan, less mess – Ideal for potlucks, bake sales, and parties
Big peanut butter flavor – In both the bars and the frosting
Perfect salty-sweet balance – Rich without being overwhelming
Feeds a crowd – Makes 16–24 generous bars
Make-ahead friendly – Even better the next day

Helpful Tips for Success

Line your pan with parchment paper for easy removal and clean edges
Cool the bars completely before frosting so the glaze sets glossy instead of soaking in
Want to switch it up? Try chocolate frosting or sprinkle the top with chopped peanuts

Peanut Butter Lunch Lady Cookie Bars

Yield: 16–24 bars
Prep Time: 15 minutes
Bake Time: 20 minutes
Total Time: 1 hour (includes cooling & frosting)

Ingredients

For the Bars

2 cups all-purpose flour
2 cups granulated sugar
1 teaspoon baking soda
1 teaspoon salt
½ cup whole milk
1 teaspoon vanilla extract
2 large eggs, beaten
1 cup (2 sticks) unsalted butter
1 cup creamy peanut butter

For the Frosting

½ cup (1 stick) unsalted butter
½ cup creamy peanut butter
2 tablespoons milk
4 cups powdered sugar

Instructions

Preheat oven to 400°F. Grease a 13×18-inch sheet pan or line with parchment paper.
Mix dry ingredients: In a large bowl, whisk together flour, sugar, baking soda, and salt.
Mix wet ingredients: In a separate bowl, whisk milk, vanilla, and beaten eggs.
Melt butter & peanut butter: In a medium saucepan, melt 1 cup butter and 1 cup peanut butter over medium heat. Bring just to a gentle boil, then remove from heat.
Combine: Stir the dry ingredients into the hot peanut butter mixture. Add the milk-egg mixture and mix until smooth.
Bake: Spread batter evenly into the prepared pan. Bake for 20 minutes, or until a toothpick inserted in the center comes out clean. Cool completely.
Make frosting: In a saucepan, melt ½ cup butter and ½ cup peanut butter. Bring just to a boil, remove from heat, stir in milk, then gradually whisk in powdered sugar until smooth.
Frost: Pour warm frosting over cooled bars and spread evenly. Let set at room temperature before slicing.