Sheet pan cookies are a true game-changer, especially when you need an easy dessert that feeds a crowd. These Peanut Butter Lunch Lady Bars are inspired by those classic school cafeteria treats — but trust me, they’re far richer, softer, and more indulgent than anything you remember from lunch line days.

Thick, chewy peanut butter cookie bars topped with a smooth, melt-in-your-mouth peanut butter frosting make this recipe pure comfort baking. Simple ingredients, no fancy steps, and guaranteed smiles with every bite.

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• Why You’ll Love This Recipe
• What You’ll Need to Make This Recipe
• How to Make This Recipe
• Tips & Variations
• Recipe Card

Why You’ll Love This Recipe

• Perfect for feeding a crowd with one pan.
• Soft, chewy texture with rich peanut butter flavor.
• No scooping individual cookies.
• Classic, nostalgic dessert that everyone loves.
• Freezer-friendly and great for make-ahead baking.

What You’ll Need to Make This Recipe

Exact measurements are listed in the recipe card at the end.

• All-purpose flour
• Granulated sugar
• Eggs
• Creamy peanut butter
• Unsalted butter
• Milk
• Baking soda
• Vanilla extract
• Salt
• Powdered sugar (for frosting)

How to Make This Recipe

Full instructions are included in the recipe card below.

1. Preheat the oven and prepare your baking sheet.
2. Mix the dry ingredients in one bowl.
3. Combine the wet ingredients separately.
4. Melt butter and peanut butter, then mix everything together.
5. Bake until set and allow to cool completely.
6. Prepare the peanut butter frosting and spread it over the bars.

Tips & Variations

• Chocolate twist: Swap the peanut butter frosting for chocolate frosting.
• Extra crunch: Add chopped peanuts or chocolate chips to the batter.
• Clean cuts: Let the bars cool fully before slicing.
• Storage: Store covered at room temperature or refrigerate for firmer bars.

Peanut Butter Lunch Lady Bars

Prep Time: 15 minutes | Bake Time: 20 minutes | Total Time: 35 minutes | Servings: 20 bars

Ingredients

• 2 cups all-purpose flour
• 2 cups granulated sugar
• 1 teaspoon baking soda
• 1 teaspoon salt
• 2 large eggs, beaten
• 1½ cups creamy peanut butter, divided
• 1½ cups unsalted butter (3 sticks), divided
• ½ cup milk + 2 tablespoons milk, divided
• 1 teaspoon vanilla extract
• 4 cups powdered sugar

Instructions

1. Preheat oven to 400°F (200°C). Grease a large cookie sheet or line with parchment paper.
2. In a bowl, combine flour, sugar, baking soda, and salt. Set aside.
3. In another bowl, whisk together eggs, ½ cup milk, and vanilla.
4. In a saucepan, melt 1 cup butter and 1 cup peanut butter until smooth.
5. Remove from heat and stir in the dry ingredients, followed by the egg mixture.
6. Spread batter evenly on the prepared pan and bake for about 20 minutes. Cool completely.
7. For frosting, bring remaining butter and peanut butter to a boil. Stir in 2 tablespoons milk.
8. Gradually whisk in powdered sugar until smooth.
9. Pour frosting over cooled bars, spread evenly, and allow to set before slicing.