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
- 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.
Enjoy!