Old-Fashioned Peanut Butter Blondies are my kind of bar cookie: chewy, rich with brown sugar, and not fussy. They bake up with set edges and a soft, fudgy center that slices clean once they’re fully cooled.
The peanut butter flavor is front and center, and the melted butter keeps the texture tender instead of cakey. I like adding chocolate chips, but I don’t always—these are still really good as plain peanut butter bars.
I make these when I want a simple dessert for a weekend, a bake sale, or a cookie tray where you need something sturdy that travels well. They’re especially good with coffee and they’re easy to portion into neat squares.
Why You’ll Love This Recipe
Soft and Chewy: These stay chewy with that classic blondie bite, and the centers keep a little fudgy feel.
Big Brown Sugar Flavor: Brown sugar gives that deeper, old-fashioned sweetness that tastes like a real blondie, not just a peanut butter cookie in a pan.
One Bowl Friendly: You’re basically whisking the batter together, then folding in the flour. Minimal mess, which I always appreciate with bar desserts.
Chocolate Chips Optional: Add them when you want a little extra, or skip them and let the peanut butter shine.
Easy to Slice and Share: Once they’re cool, they cut into tidy squares that hold up well for lunches, potlucks, and cookie trays.
Ingredients You’ll Need
Pan and dry mix
- All-purpose flour: I use regular flour here. It gives the bars enough structure so the centers stay soft without falling apart.
- Baking powder: Just enough lift to keep the blondies from feeling heavy. Don’t swap in baking soda unless you’re changing the recipe more.
- Fine salt: Don’t skip it—peanut butter and brown sugar both need salt to taste right.
- Semisweet chocolate chips: Optional, but really nice. Semisweet is my go-to, and mini chips work well too if you want more even chocolate in every bite.
Batter
- Unsalted butter: Melted butter keeps these dense and chewy instead of fluffy. Let it cool a bit so it doesn’t scramble the eggs.
- Creamy peanut butter: Creamy gives the smoothest texture, but crunchy is great if you want little bits throughout.
- Light brown sugar: This is where that old-fashioned blondie flavor comes from. Dark brown sugar works too if you want a deeper molasses note.
- Eggs: Room temperature eggs mix in easier and help the batter get glossy.
- Vanilla extract: It rounds everything out and makes the peanut butter taste more “baked” and dessert-like.
Recipe Instructions
- Preheat the oven: Heat the oven to 350°F and set a rack in the middle. Line a 9×13-inch pan with parchment paper (or grease it well).
- Mix the dry ingredients: In a medium bowl, whisk the flour, baking powder, and salt until evenly combined.
- Mix the butter and peanut butter: In a large bowl, whisk the melted butter, peanut butter, and brown sugar until smooth and glossy.
- Add the eggs: Whisk in the eggs one at a time, mixing well after each, then whisk in the vanilla.
- Add the dry ingredients: Fold the flour mixture into the wet mixture just until you don’t see dry streaks.
- Add the chocolate chips: Fold in the chocolate chips if you’re using them.
- Spread the batter: Scrape the batter into the prepared pan and spread it into an even layer, getting into the corners.
- Bake: Bake for 22 to 28 minutes, until the edges are set and a toothpick in the center comes out with a few moist crumbs.
- Cool: Let the blondies cool completely in the pan, then lift out using the parchment and slice into squares.
Some of my tips!
This is the part that really makes a difference. If you only read one section, make it this one because this is where I share the little trick that helps the recipe turn out so well.
Recipe Tips & Tricks
Don’t overbake. Pull them when the edges look set and the center still looks a little soft. They’ll firm up as they cool, and that’s what keeps them chewy.
Cool them all the way before slicing. If you cut too soon, the middle can stick to the knife and the squares won’t look as clean. I usually give it at least an hour, sometimes longer.
Use parchment if you can. It makes lifting the whole slab out of the pan simple, and it keeps the edges from sticking.
Crunchy peanut butter is fair game. It adds little bits of texture throughout, which is really nice if you’re skipping the chocolate chips.
Try a chip swap. I like trading out up to half the chocolate chips for peanut butter chips or chopped peanuts when I want a more peanut-forward batch.
Make some touches!
There are plenty of easy ways to serve this depending on the occasion. Keep it simple, or add a few small touches to make it feel a little more special.
Serving Suggestions
- Milk: A cold glass of milk is classic with peanut butter bars. This is the simple choice, especially if you add chocolate chips.
- Coffee: These are really good with coffee, hot or iced. I like them most with plain coffee or a latte.
- Ice cream: Serve a square with vanilla ice cream on the side. If you warm the blondie slightly, keep it brief so it stays chewy.
- Fruit: Strawberries or raspberries are nice alongside a rich bar like this. It keeps the plate from feeling too heavy.
Save it for later
This section covers how to store leftovers and what parts of the recipe you can prepare ahead of time.
Storage and Make Ahead
Store the blondies covered at room temperature for 2 to 3 days. If your kitchen runs warm, I’ll move them to the fridge so they don’t get too soft.
Store leftovers covered in the fridge for up to 4 days. They’ll firm up when cold, which is fine, but I like a quick 10 to 15 seconds in the microwave to soften a piece.
You can make these ahead for parties or cookie trays. Bake them the day before, keep them covered, and slice right before serving if you want the neatest edges.
If you want them to last longer, freeze individual portions in an airtight container. Thaw in the fridge overnight or at room temperature for a bit before eating.
A few quick answers
This section covers a few extra details that may help before you head to the recipe card.
Recipe FAQs
How do I know when peanut butter blondies are done?
Look for set, lightly browned edges and a center that no longer looks wet. A toothpick in the middle should come out with a few moist crumbs, not clean.
Can I use crunchy peanut butter?
Yes. Crunchy peanut butter works well here and gives the bars a little extra texture. Everything else stays the same.
Can I bake these in a 9×9-inch pan instead?
You can for thicker blondies. Plan to add about 5 to 10 minutes to the bake time, and use the toothpick test in the center to judge doneness.
What mix-ins work besides chocolate chips?
Peanut butter chips are great, and chopped peanuts add a nice crunch. I usually swap up to about half the chocolate chips so the batter isn’t too packed with add-ins.
Why did my blondies turn out dry?
Most of the time it’s from baking a little too long. Ovens vary, so I start checking early, and I pull them while the center still looks slightly soft.
You might also like
Before you go, take a look at a few other recipes below the recipe card. They use similar ingredients in a different way and are worth saving too.
MORE DINNER RECIPES TO TRY
Old-Fashioned Peanut Butter Blondies
INGREDIENTS
Pan and dry mix
- 2 cups all-purpose flour
- 1 tsp baking powder
- 1 tsp fine salt
- 1 cup semisweet chocolate chips optional.
Batter
- 1/2 cup unsalted butter melted and slightly cooled
- 1 cup creamy peanut butter
- 1 1/2 cups packed light brown sugar
- 2 large eggs room temperature
- 2 tsp vanilla extract.
INSTRUCTIONS
Prep
- Heat oven to 350 F and position rack in the middle
- line a 9x13 inch pan with parchment or grease well
- whisk flour baking powder and salt until evenly combined.
Mix and bake
- Whisk melted butter peanut butter and brown sugar until smooth and glossy
- whisk in eggs one at a time then vanilla
- fold in dry ingredients just until no dry streaks remain and fold in chips if using
- spread batter evenly in the prepared pan
- bake until edges are set and a toothpick in the center comes out with a few moist crumbs 22 to 28 minutes
- cool completely in the pan then lift out and slice.
