Peanut Butter Bars
These peanut butter bars feature a soft and chewy oat cookie base layered with creamy peanut butter and topped with a rich chocolate frosting. They're a nostalgic dessert that's perfect for parties, bake sales, lunchboxes, and family gatherings.
Equipment
- 18 x 13-inch rimmed baking sheet
- Large mixing bowl
- Electric mixer or stand mixer
- Rubber spatula
- Medium saucepan
- Whisk
- Measuring cups and spoons
Ingredients
For the Bars
- 2 cups all-purpose flour
- 2 cups quick-cooking oats
- 1 teaspoon baking soda
- ¼ teaspoon salt
- 1 cup unsalted butter, softened
- 1¼ cups packed light brown sugar
- ¾ cup granulated sugar
- 2 large eggs
- 1 cup creamy peanut butter
- 1 teaspoon vanilla extract
Peanut Butter Layer
- 1 cup creamy peanut butter
Chocolate Frosting
- ½ cup unsalted butter, cut into pieces
- ¼ cup unsweetened cocoa powder
- ¼ cup milk
- 2 pinches salt
- 1 teaspoon vanilla extract
- 3 cups powdered sugar
Instructions
- Preheat the oven to 350°F (175°C). Lightly coat a rimmed baking sheet with nonstick cooking spray.
- In a large bowl, combine the flour, oats, baking soda, and salt. Set aside.
- In a separate mixing bowl, beat the softened butter, brown sugar, and granulated sugar until light and fluffy.
- Add the eggs one at a time, mixing well after each addition.
- Blend in the peanut butter and vanilla extract until smooth.
- Gradually add the dry ingredients and mix just until a soft dough forms.
- Transfer the dough to the prepared baking sheet. Lightly grease your hands and press the dough into an even layer covering the pan.
- Bake for approximately 12 minutes, or until the bars are puffed and just beginning to set. Avoid overbaking to keep the bars soft and chewy.
- Remove the pan from the oven and allow it to cool for about 5 minutes.
- Drop spoonfuls of the remaining peanut butter over the warm bars. Let it soften for a minute, then spread into a smooth layer covering the entire surface.
- To prepare the frosting, melt the butter in a medium saucepan over medium heat.
- Stir in the cocoa powder, milk, and salt. Bring the mixture just to a gentle boil while stirring constantly.
- Remove from the heat and whisk in the vanilla extract.
- Add the powdered sugar and stir until the frosting is smooth. If needed, add a tablespoon of hot water to achieve a spreadable consistency.
- Immediately pour the frosting over the peanut butter layer and spread evenly.
- Let the frosting set completely before slicing into bars and serving.
Notes
- Do not wait for the bars to become deeply golden. They should still feel soft when removed from the oven.
- Overbaking can result in dry edges and a firmer texture.
- For easier slicing, allow the frosting to fully set before cutting.
- Store in an airtight container at room temperature for up to 4 days.
- Refrigerate for up to 1 week for longer freshness.
- Chopped peanuts can be sprinkled over the frosting before it sets for extra crunch.
- These bars freeze well for up to 2 months when stored in a freezer-safe container.