3-Ingredient Peanut Butter Blondies
If you have peanut butter, brown sugar, and an egg in the kitchen, you are already most of the way to dessert.
These 3-Ingredient Peanut Butter Blondies are rich, chewy, and packed with peanut butter flavor, but they don’t require flour, butter, baking powder, or a long list of ingredients. Everything gets mixed together in one bowl, spread into a small baking pan, and baked until the edges are set and the middle is still wonderfully soft.
They remind me of the center of a really good peanut butter cookie, only thicker and fudgier.
This is exactly the sort of recipe I like when I want something homemade but don’t feel like turning baking into a project. The batter takes only a few minutes to put together, and there isn’t much cleanup afterward.
Just make sure you give the blondies enough time to cool before slicing. That’s probably the hardest part of the entire recipe.
Why You’ll Love These Peanut Butter Blondies
The obvious reason is the ingredient list.
You only need three ingredients, and they’re all things you may already have sitting in the pantry or refrigerator.
But simplicity isn’t the only reason these are worth making.
The peanut butter gives the bars a rich, nutty flavor and helps create their dense texture. Brown sugar brings sweetness along with a deeper caramel flavor, while the egg holds everything together as the blondies bake.
They’re also:
- Flourless
- Made without butter or oil
- Mixed in one bowl
- Ready with very little preparation
- Soft and chewy in the middle
- Great for peanut butter lovers
- Easy to cut into bars for sharing
And because there is no flour to measure, there isn’t much that can go wrong as long as you don’t overbake them.
What Do 3-Ingredient Peanut Butter Blondies Taste Like?
These aren’t exactly the same as a traditional blondie made with butter and flour.
They’re denser.
Think of something somewhere between a soft peanut butter cookie and a fudgy blondie.
The edges become slightly firmer and chewier while the center stays soft and rich. Brown sugar adds a warm caramel note that works especially well with the salty nuttiness of peanut butter.
They are sweet, but the peanut butter keeps that sweetness from tasting flat.
A glass of cold milk alongside one of these is hard to beat.
The Only 3 Ingredients You Need
Creamy Peanut Butter
Peanut butter does most of the work in this recipe.
It provides flavor, fat, structure, and that rich texture that makes these bars feel much more substantial than their three-ingredient list suggests.
For the most consistent results, I like using a regular creamy peanut butter such as Jif or Skippy rather than an especially runny natural peanut butter.
Natural peanut butter can separate significantly, which can change the texture of the batter.
If natural peanut butter is what you have, stir it extremely well before measuring.
Brown Sugar
Brown sugar provides more than sweetness.
Its molasses flavor adds that warm, almost caramel-like note associated with blondies and helps keep the centers softer.
Light brown sugar works perfectly.
Dark brown sugar can also be used if you prefer a slightly deeper molasses flavor.
Make sure you pack the sugar into the measuring cup.
Egg
One large egg brings everything together.
It gives the blondies enough structure to hold their shape once cooled without making them cakey.
Use a large egg for the proportions in this recipe.
How to Make 3-Ingredient Peanut Butter Blondies
You won’t need a mixer for this recipe.
A bowl and sturdy spoon or spatula are enough.
Prepare the Pan
Preheat the oven to 350°F.
Line an 8-by-8-inch baking pan with parchment paper, leaving a little extra parchment extending over two sides.
That overhang makes it much easier to lift the cooled blondies out of the pan.
You can lightly grease the pan instead, but parchment gives cleaner slices.
Mix the Batter
Add the peanut butter, packed brown sugar, and egg to a medium mixing bowl.
Stir until everything is completely combined.
At first, the mixture may look slightly loose, but it quickly turns into a thick, sticky batter.
Keep stirring until you no longer see streaks of egg or pockets of brown sugar.
Spread It Into the Pan
Transfer the batter to your prepared baking pan.
Because the mixture is quite thick, it won’t spread itself out like brownie batter.
Use a spatula or the back of a spoon to gently press it toward the corners and smooth the surface into an even layer.
Bake
Bake the blondies for approximately 20 to 25 minutes.
You’re looking for lightly browned edges and a center that appears set but still slightly soft.
Do not wait until the entire surface looks dry and firm.
The bars continue to set as they cool, and baking them too long is the easiest way to lose that soft, chewy center.
Cool Completely
This part matters.
Allow the blondies to cool completely in the pan before cutting.
Fresh from the oven, they will be very soft and may seem like they aren’t firm enough to slice. As they cool, the peanut butter and sugar mixture sets considerably.
Once cool, use the parchment paper to lift them out of the pan and cut them into squares.
How to Tell When Peanut Butter Blondies Are Done
With flourless bars, a traditional toothpick test isn’t always the best indicator.
Instead, watch the edges and center.
The edges should look firm and slightly darker than the middle.
The center should no longer look wet, but it doesn’t need to feel completely firm while the pan is still hot.
If you press the middle very gently, it should feel set with just a little softness.
For chewy blondies, it is better to remove them slightly early than to leave them in the oven several minutes too long.
They’ll continue firming up while they cool.
Don’t Overbake Them
This is probably the most important tip in the entire recipe.
Peanut butter can go from wonderfully soft to dry surprisingly quickly in the oven.
Start checking around the 20-minute mark.
The exact cooking time can vary depending on your oven, baking pan, and peanut butter.
A metal pan can also bake differently from a thick ceramic or glass baking dish.
Once the edges are set and the center no longer looks raw, take them out.
Use the Right Size Pan
An 8-by-8-inch pan gives these blondies a nice thickness.
Using a significantly larger pan will spread the batter too thin and can cause it to bake much faster.
If you only have a larger baking pan, don’t spread the batter over the entire surface. Keep it in a smaller section if possible.
Let Them Cool Before Slicing
I know warm peanut butter bars are tempting.
But if you cut these immediately after baking, they can fall apart.
Cooling isn’t just about temperature here; it’s part of the recipe.
As the bars cool, the sugars and peanut butter firm up and create that dense, chewy blondie texture.
For the cleanest squares, let them cool completely.
If you want an especially clean cut, you can even refrigerate the pan briefly before slicing.
Can I Use Crunchy Peanut Butter?
Absolutely.
Crunchy peanut butter gives you little pieces of peanut throughout each bar.
The texture won’t be quite as smooth, but the flavor is excellent.
Use the same amount as you would creamy peanut butter.
Can I Use Natural Peanut Butter?
You can, but the results can vary.
Traditional creamy peanut butter tends to be more stable because the oils don’t separate as dramatically.
If you’re using natural peanut butter, make sure the jar is thoroughly stirred before measuring.
You don’t want to scoop mostly oil from the top or very dry peanut butter from the bottom.
Your finished blondies may also be a little softer depending on the brand.
Easy Add-Ins
The basic recipe really does need only three ingredients.
But if you don’t mind turning your three-ingredient blondies into four-ingredient blondies, there are plenty of ways to change them.
Try folding in:
- Chocolate chips
- Chopped peanuts
- Peanut butter chips
- White chocolate chips
- Mini chocolate chips
- Chopped chocolate
- Toffee pieces
Chocolate and peanut butter are obviously a great combination, so semisweet chocolate chips would be my first choice.
About 1/2 cup is plenty.
Add a Little Sea Salt
If you don’t mind adding one optional extra, a tiny sprinkle of flaky sea salt over the top can make these even better.
The salt cuts through some of the sweetness and makes the peanut butter flavor stand out.
Just don’t add too much, especially if your peanut butter is already salted.
How to Serve Peanut Butter Blondies
They’re perfectly good all by themselves.
That’s usually how I eat them.
But for dessert, you can warm a blondie slightly and serve it with a scoop of vanilla ice cream.
A drizzle of melted chocolate also works beautifully.
For a really peanut-butter-heavy dessert, warm a spoonful of peanut butter and drizzle it across the top.
You could also serve the bars alongside:
- Cold milk
- Coffee
- Vanilla ice cream
- Chocolate ice cream
- Fresh strawberries or raspberries
- Whipped cream
How to Get Clean Blondie Squares
Wait until the blondies are completely cool.
Lift the entire slab from the pan using the parchment overhang and place it on a cutting board.
Use a sharp knife and make one clean downward cut rather than sawing back and forth.
Wipe the knife between cuts if peanut butter residue starts sticking to the blade.
For 9 generous blondies, make two cuts in each direction.
For smaller treats, cut them into 16 squares.
How to Store Peanut Butter Blondies
Once completely cool, place the blondies in an airtight container.
They can be kept at room temperature for approximately 3 to 4 days.
Keep the container closed tightly so the bars don’t dry out.
If your kitchen is especially warm, you can store them in the refrigerator instead.
Refrigerated blondies will become firmer, so I like letting them sit at room temperature for a few minutes before eating.
Can You Freeze Peanut Butter Blondies?
Yes.
These are easy to freeze individually.
Allow the blondies to cool completely, then cut them into squares.
Wrap each square or separate layers with parchment paper before placing everything in a freezer-safe container or bag.
Freeze for up to about 2 months.
When you’re ready for one, let it thaw at room temperature.
You can also warm it very briefly in the microwave if you prefer a softer blondie.
Can I Double the Recipe?
Yes.
For a larger batch, double all three ingredients and use a larger baking pan.
Keep in mind that changing the thickness of the batter will affect baking time.
Rather than relying on the timer alone, watch for those same visual signs: set edges and a center that no longer looks wet.
Are These Traditional Blondies?
Not exactly.
Traditional blondies usually contain flour, butter, sugar, eggs, and often vanilla.
This is a simplified flourless version designed around the same idea of a rich, chewy dessert bar.
The texture is denser and more peanut-butter-forward than a classic blondie.
If you like soft peanut butter cookies, chances are you’ll enjoy these.
Frequently Asked Questions
Do 3-Ingredient Peanut Butter Blondies really need no flour?
That’s right.
The peanut butter and egg provide enough structure for these bars to hold together once baked and cooled.
The texture is denser than a flour-based blondie, which is part of what makes them so rich.
Do I need baking powder or baking soda?
No.
These blondies aren’t supposed to rise like a cake.
Leaving out leavening helps preserve their dense, chewy texture.
Why are my blondies falling apart?
The most common reason is cutting them while they’re still warm.
These bars firm considerably as they cool.
Let them cool completely before removing them from the pan and slicing.
Why did my blondies turn out dry?
They were probably baked a little too long.
Because the ingredient list is so simple, a few extra minutes in the oven can noticeably affect the final texture.
Start checking early.
Can I reduce the brown sugar?
You can experiment, but I wouldn’t reduce it dramatically.
Sugar contributes to both the sweetness and texture of these blondies.
Using substantially less can produce a drier, more crumbly result.
Should I refrigerate them?
You don’t have to if they’ll be eaten within a few days.
Store them tightly covered at room temperature.
Refrigeration is useful if your kitchen is very warm or you want to keep them a little longer.
The Kind of Dessert Recipe Worth Keeping
There are times when I enjoy a baking project with several bowls and a long ingredient list.
This isn’t one of those recipes.
These 3-Ingredient Peanut Butter Blondies are for the days when you want something sweet and homemade without making much of a mess.
One bowl.
Three ingredients.
A few minutes of mixing.
And after a short trip through the oven, you have chewy peanut butter bars with caramel-like sweetness around the edges and a soft, rich center.
It’s hard to ask for much more from three ingredients.
3-Ingredient Peanut Butter Blondies Recipe
Ingredients
- 1 cup creamy peanut butter
- 1 cup packed light brown sugar
- 1 large egg
Instructions
- Preheat the oven to 350°F (175°C). Line an 8-by-8-inch baking pan with parchment paper, leaving some overhang along two sides.
- Add the peanut butter, packed brown sugar, and egg to a medium bowl.
- Stir until the mixture is smooth, thick, and completely combined.
- Transfer the batter to the prepared pan and use a spatula to press and spread it into an even layer.
- Bake for 20 to 25 minutes, checking near the 20-minute mark. The edges should be set and lightly browned while the center should look set but remain slightly soft.
- Remove the pan from the oven and allow the blondies to cool completely.
- Lift them from the pan using the parchment paper and cut into 9 squares.
Notes
- Regular creamy peanut butter generally gives the most consistent texture. If using natural peanut butter, stir it thoroughly before measuring.
- Avoid overbaking. These blondies continue to firm as they cool, so the center doesn't need to feel completely firm when they leave the oven.
- For smaller servings, cut the pan into 16 squares instead of 9.
