Description

Delicious and classic Lunch Lady Peanut Butter Bars with a crispy peanut butter oatmeal cookie base, topped with a smooth peanut butter layer and rich chocolate frosting. These bars combine creamy peanut butter, oats, and cocoa for a nostalgic treat perfect for lunchboxes or dessert.

Ingredients

Scale

Peanut Butter Oatmeal Cookie Base

1 cup salted butter, softened (227g)
1 cup granulated sugar (200g)
1 cup packed light brown sugar (200g)
1 cup creamy peanut butter (divided)
2 large eggs
2 teaspoons vanilla extract
2 cups all-purpose flour, scooped & leveled (282g)
2 cups old-fashioned oats
1 teaspoon baking soda
1 teaspoon salt

Peanut Butter Topping

1 1/2 cups creamy peanut butter

Chocolate Frosting

1/2 cup salted butter, softened (114g)
3 cups powdered sugar
4 tablespoons cocoa powder
1/4 cup milk
2 teaspoons vanilla extract

Instructions

Preheat and Prepare Pan: Preheat your oven to 350°F (177°C). Spray a half-sheet baking sheet (13″x18″) generously with baking spray to prevent sticking.
Make the Cookie Dough: In a mixing bowl, beat the softened butter, granulated sugar, brown sugar, and 1 cup of peanut butter until creamy and light in color. Add the eggs and vanilla extract, then beat again, scraping down the sides and bottom of the bowl to ensure everything is well combined.
Add Dry Ingredients: Add the flour, oats, baking soda, and salt to the wet mixture. Mix gently just until combined, being careful not to overmix. Then spread the dough evenly into the prepared baking sheet using a spatula.
Bake the Base: Bake the peanut butter oatmeal cookie base for 15-17 minutes until the edges turn golden brown and the center is barely set. Avoid overbaking to keep bars chewy and moist.
Apply Peanut Butter Layer: While the cookie base is still warm, melt the remaining 1 1/2 cups of peanut butter in the microwave for 1 minute in a microwave-safe bowl. Drizzle the melted peanut butter evenly over the baked base and spread it with a spatula or knife to create a smooth layer. Allow it to cool completely until firm; you may refrigerate to speed up the process.
Prepare Chocolate Frosting: In a large bowl, beat the softened butter, powdered sugar, cocoa powder, milk, and vanilla extract together until smooth and creamy.
Frost the Bars: Spread the chocolate frosting evenly over the cooled peanut butter layer. Once frosted, cut the bars into squares and serve.

Notes

Do not overbake the cookie base; it should be slightly soft in the center when removed from the oven.
For easier spreading, melt the peanut butter slowly and stir to ensure smoothness.
Refrigerate bars after adding peanut butter layer to help it set faster before frosting.
Store baked bars in an airtight container at room temperature for up to 3 days or refrigerate for up to a week.
Use creamy peanut butter for the best texture and spreadability.

Prep Time: 15 minutes
Cook Time: 17 minutes
Category: Dessert
Method: Baking
Cuisine: American

Keywords: peanut butter bars, lunch lady bars, peanut butter dessert, chocolate frosting, oatmeal bars, peanut butter oatmeal cookies