These peanut butter blondies are soft and chewy with a rich peanut butter flavor and a generous mix of Reese’s Pieces and chocolate chips. A quick, easy, one‑bowl recipe with no mixer required.
This post was updated September 5, 2024 with new photos and recipe tips
These peanut butter blondies pack the flavor of classic peanut butter cookies into a fudgy, chewy blondie. They have a brownie‑like texture but an unmistakable peanut butter taste thanks to peanut butter in the batter and the mix‑ins of Reese’s Pieces and chocolate chips. If you love thick, extra chewy bars that are almost gooey, these are for you.
Warning — for true peanut butter lovers only.
Peanut Butter Blondie Recipe
I first shared this recipe back in 2015, and after testing I updated it to be chewier, to balance the peanut butter flavor without making it overly rich, and to yield a larger batch.
Ingredients:
- 2/3 cup unsalted butter (170 g)
- 2 cups light brown sugar (420 g) — or 1 cup dark brown + 1 cup white sugar
- 3/4 cup smooth peanut butter (about 270 g)
- 3 large eggs
- 2 teaspoons vanilla extract
- 2 cups all‑purpose flour (250 g)
- 1/4 teaspoon salt
- 3/4 cup Reese’s Pieces (about 140 g)
- 3/4 cup chocolate chips (about 120 g)
Note: This recipe omits baking powder and baking soda to keep the blondies dense and chewy rather than cake‑like.
The method is simple and done in one bowl without a mixer. Melt the butter and peanut butter together, then whisk in the brown sugar until smooth. Whisk in the eggs and vanilla, then gently fold in the flour and salt until no streaks remain. Fold in the Reese’s Pieces and chocolate chips, pour the batter into a prepared pan, and bake.
You can swap the mix‑ins to suit your taste—use all Reese’s Pieces, peanut butter chips, chocolate chips, or chopped peanut butter cups. To keep the blondies moist and chewy, avoid overbaking. In my oven, about 30 minutes is ideal; metal pans tend to bake edges a bit faster than glass or ceramic.
Optional frosting: If you’d like frostings, a peanut butter buttercream will make these very rich and extra peanut buttery.
These blondies taste like thick, ultra‑soft peanut butter cookies with a brownie‑style chew. The recipe makes a large batch, so there’s usually enough for seconds.
For more peanut butter recipes, consider trying peanut butter chocolate chip cookies, peanut butter fudge, or peanut butter oatmeal cookies.
Peanut Butter Blondies
Equipment
- 9×13 inch (23 x 33 cm) baking pan — see notes for alternatives
Ingredients
- 2/3 cup unsalted butter (170 grams)
- 3/4 cup peanut butter (about 270 grams)
- 2 cups light brown sugar (420 grams)
- 2 teaspoons vanilla extract
- 3 large eggs
- 2 cups all‑purpose flour (250 grams)
- 1/4 teaspoon salt
- 3/4 cup Reese’s Pieces (about 140 grams)
- 3/4 cup chocolate chips (about 120 grams)
Instructions
- Preheat the oven to 350°F (180°C). Line a 9×13 inch pan with parchment, leaving an overhang, or lightly grease the pan.
- In a large microwave‑safe bowl, melt the butter and peanut butter together. Stir until smooth.
- Whisk the brown sugar into the peanut butter mixture. Add the eggs and vanilla and whisk until evenly combined.
- Gently fold in the flour and salt. Stop once there are no visible streaks or lumps of flour.
- Fold in the Reese’s Pieces and chocolate chips.
- Spread the batter evenly into the prepared pan.
- Bake about 30 minutes, or until the top looks set and a toothpick inserted in the center comes out clean or with a few damp crumbs. For less gooey bars, bake up to 35 minutes.
- Cool the bars in the pan. If you used parchment, lift the blondies out by the overhang and slice with a sharp knife. I cooled mine about 2½ hours; the mix‑ins remained a bit melty.
Notes
- Peanut butter: Smooth peanut butter is recommended; crunchy is fine. Avoid natural or homemade peanut butter in baking, as separation can affect texture.
- Mix‑ins: Use up to 1½ cups total of your favorite mix‑ins (chocolate chips, peanut butter chips, Reese’s Pieces, or chopped peanut butter cups).
- Smaller batch: Use an 8×8 inch (20×20 cm) pan and reduce bake time to about 25 minutes. Scaled ingredients for an 8×8 are listed below:
- 1/3 cup unsalted butter
- 1/4 cup + 2 tbsp peanut butter
- 1 cup brown sugar
- 1 tsp vanilla
- 1 large egg + 1 egg yolk
- 1 cup all‑purpose flour
- Pinch of salt
- 6 tbsp Reese’s Pieces
- 6 tbsp chocolate chips
- Storage: Store airtight at room temperature up to 4 days. Freeze cooled blondies in an airtight container for up to 2 months with wax paper between layers to prevent sticking. Thaw in the fridge.
- Nutrition: Nutritional values are estimates based on 1 blondie when the pan yields 15 large bars.
Nutrition