Old-School Peanut Butter Cookie Bars (Lunch Lady Style)
There’s something timeless about classic cafeteria desserts—simple to make, big on flavor, and crafted to feed a crowd. These Peanut Butter Cookie Bars are a modern spin on those nostalgic lunch lady treats, and they’re every bit as crave-worthy.

Unlike cookies that require scooping and chilling, these bars are baked in a single sheet pan. No fuss, no waiting—just spread the batter and bake. The end result? Buttery, peanut-butter-packed bars with a soft, almost brownie-like texture that melts in your mouth.

And then comes the glaze. A warm, creamy peanut butter frosting is poured over the cooled bars, soaking in just enough to create a rich, sweet top layer that sets beautifully. These bars disappear fast—especially if friends or family catch wind of them.

Why You’ll Love This Recipe
One pan, zero hassle – Quick to make and easy to clean up.

Double peanut butter punch – It’s in the base and the glaze.

Sweet meets salty – A flavor duo that never fails.

Great for gatherings – Yields up to two dozen servings.

Even better the next day – The texture softens, the flavors deepen.

Baking Tips
Use parchment paper for easy lifting and clean edges.

Cool completely before frosting—this ensures a smooth, glossy glaze.

Switch it up by adding chocolate chips, using a chocolate glaze, or topping with chopped peanuts.

Recipe: Peanut Butter Cookie Bars
Yield: 16–24 bars
Prep Time: 15 minutes
Bake Time: 20 minutes
Total Time: 1 hour (cooling & frosting included)

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

Instructions
Preheat the oven to 400°F (200°C). Grease or line a 13×18-inch sheet pan with parchment paper.

Mix the dry ingredients: In a large bowl, whisk together the flour, sugar, baking soda, and salt.

Blend the wet ingredients: In a separate bowl, stir together the milk, vanilla, and beaten eggs.

Heat the base: In a saucepan, melt butter and peanut butter over medium heat until bubbling gently. Remove from heat.

Combine: Stir the dry ingredients into the warm peanut butter mixture. Add the egg mixture and mix until smooth.

Bake: Spread the batter evenly in the pan. Bake for 20 minutes, or until a toothpick comes out clean. Cool completely.

Prepare the glaze: Melt butter and peanut butter in a saucepan. Remove from heat, stir in milk, then gradually whisk in powdered sugar until smooth.

Frost the bars: Pour warm glaze over the cooled bars. Spread evenly and let set.

Storage Tips
Counter: Store covered for up to 3 days.

Refrigerator: Keeps well for up to 7 days (let warm to room temp before serving).

Freezer: Wrap tightly and freeze for up to 2 months. Thaw overnight.