These thick, chewy peanut butter Oreo blondies combine bold peanut butter flavor with whole Oreos baked into every bite. Think of them as a peanut butter cookie and an Oreo merged into one — simple to make and dangerously delicious! 
These peanut butter Oreo blondies are a companion to my Oreo brownies and Oreo chocolate chip cookie bars. The result is a dense, chewy blondie with plenty of peanut butter taste and Oreo cookies scattered throughout. They’re thick, comforting, and satisfy any craving for something sweet and slightly nostalgic.
The recipe is a small homage to an old friend. When we were kids she used to spread peanut butter on an Oreo as an after-school snack — a brilliant combination. These bars capture that same idea but turn it into a shareable dessert that takes only a little extra effort beyond the original snack. 
To prepare the batter, start by mixing melted butter, brown sugar, and peanut butter until smooth. Stir in the eggs and vanilla, then gently fold in the flour and salt. The dough comes together quickly — under 10 minutes. There’s no baking powder or baking soda in this recipe by design: leaving those out keeps the bars dense and chewy rather than light and cake-like.
When assembling the bars, lightly grease your pan before lining it with parchment paper so the paper stays in place and spreading the batter is easier.
- Spread about half of the peanut butter blondie batter into the bottom of the prepared pan to form an even layer.
- Arrange a layer of Oreo cookies over the peanut butter base and press them down lightly.
- Drop spoonfuls of the remaining dough over the Oreo layer so the cookies are covered in small mounds of dough.
- Carefully spread the dough to cover the Oreos evenly, smoothing the top with a spatula or flat knife.
Dropping spoonfuls of dough instead of dumping it all at once makes it easier to cover the Oreos evenly.
Bake the bars in a preheated oven for about 23–27 minutes, or until the top is set and a toothpick comes out clean or with a few moist crumbs. Baking time will vary with ovens and depends on whether you prefer slightly gooey centers or firmer blondies.
For neat slices like the photos, allow the bars to cool completely before cutting. It’s the hardest step, but worth the patience. 
The finished bars are dense and chewy with Oreo pockets that elevate the texture and flavor. If you enjoy peanut butter desserts, try other recipes like peanut butter cheesecake bars or peanut butter chocolate chip cookies for more ideas.
- Peanut Butter Cheesecake Bars
- Peanut Butter Chocolate Chip Cookies — big, bakery-style cookies
Peanut Butter Oreo Blondies
Equipment
- 8×8 inch (20×20 cm) pan
Ingredients
- 1/2 cup unsalted butter (112 grams), melted
- 1 1/2 cups brown sugar (158 grams), light or dark
- 2/3 cup peanut butter
- 1 teaspoon vanilla extract
- 2 large eggs
- 1 1/2 cups all-purpose flour (188 grams)
- 1/4 teaspoon salt
- 18 Oreo cookies
Instructions
- Preheat the oven to 350°F (180°C).
- Lightly grease an 8×8 inch (20×20 cm) pan, then line it with parchment paper, leaving an overhang to lift the bars out later.
- In a large bowl, whisk together the melted butter, brown sugar, and peanut butter until smooth.
- Mix in the eggs and vanilla until combined.
- Gently fold in the flour and salt until no dry streaks remain. Do not overmix.
- Spread about half of the batter evenly in the prepared pan.
- Arrange a layer of Oreos over the batter and press them down slightly (four rows of four are a good fit for an 8×8 pan).
- Drop spoonfuls of the remaining batter across the Oreos so it’s distributed evenly.
- Smooth the top with a flat knife or spatula so the Oreos are fully covered.
- Bake 23–27 minutes, until the top looks set and a toothpick returns clean or with a few moist crumbs. Adjust time for your preferred gooeyness.
- Cool completely for clean slices. Use the parchment overhang to lift the slab from the pan, then slice with a sharp knife.
Notes
- Peanut Butter: Use a smooth, commercial peanut butter for consistent texture and results. Avoid natural peanut butter that separates, as oil content varies and can affect the batter.
- Storage: Keep bars in an airtight container at room temperature for up to 4 days. For longer storage, freeze tightly wrapped bars for up to 2 months and thaw in the refrigerator.
- Nutrition: Nutrition info is an estimate per blondie, assuming the pan yields 12 equal pieces.
Nutrition