Soft Peanut Butter Cookie Bars are my go-to when I want the comfort of a peanut butter cookie but in easy bar form. They’re soft and chewy, bake in one pan, and slice cleanly into squares that are simple to serve.
The flavor is that classic peanut butter + brown sugar combo, with a cookie texture that stays tender instead of turning cakey. I like this version because it’s reliable: set edges, a center that stays just soft, and the option to add chocolate chips when I’m in the mood.
These are especially good on a cookie tray, for weekend baking, or anytime you need a dessert that travels well. I’ll often finish them with a tiny pinch of flaky salt if I’m serving them with coffee.
Why You’ll Love This Recipe
One-pan baking: Everything bakes in a 9×13, so you get cookie-bar payoff without scooping dozens of cookies.
Soft and chewy: The centers stay tender and chewy, with edges that set up just enough to slice neatly.
Big peanut butter flavor: These actually taste like peanut butter cookies, not just “sweet bars with a hint of PB.”
Easy to slice and serve: They’re sturdy enough to hold, so they work well for lunches, bake sales, and platters.
Customizable: Chocolate chips are great here, but peanut butter chips or chopped peanuts work just as well.
Ingredients You’ll Need
Dry Ingredients
- All-purpose flour: I use regular flour here. Measuring accurately matters so the bars stay chewy instead of dry.
- Baking soda: Helps the bars spread and gives that classic cookie texture.
- Baking powder: A little lift so the middle doesn’t bake up dense.
- Cornstarch: This is where a lot of the soft chew comes from. It helps the bars stay tender even after they cool.
- Fine salt: Don’t skip it. Peanut butter needs salt to taste like peanut butter.
Wet Ingredients
- Creamy peanut butter: Creamy is my default, but crunchy works too if you want little bits throughout. I stick with shelf-stable peanut butter (like the usual jarred kind) for the most consistent texture.
- Light brown sugar: This keeps the bars chewy and gives that deeper “cookie” flavor. Dark brown sugar works too if that’s what you have.
- Granulated sugar: Helps the edges set and adds a little crispness around the sides.
- Unsalted butter: Softened butter blends in smoothly so the batter isn’t lumpy. If your butter is melted, the batter can get too loose.
- Eggs: Room temperature mixes in easier, but cold eggs are fine—just beat a little longer.
- Vanilla extract: It makes the bars taste more like a real cookie and less like plain peanut butter.
Optional Mix Ins
- Semi-sweet chocolate chips: Semisweet is my go-to here. Milk chocolate is fine if you want it sweeter.
- Flaky salt: Totally optional, but I like a light sprinkle on top, especially if you add chocolate chips.
Recipe Instructions
- Preheat the oven: Heat the oven to 350°F. Line a 9×13-inch baking pan with parchment paper and lightly grease it.
- Mix the dry ingredients: Whisk the flour, baking soda, baking powder, cornstarch, and salt together in a bowl, then set aside.
- Beat the butter and peanut butter: In a large bowl, beat the softened butter and peanut butter until smooth.
- Add the sugars: Beat in the brown sugar and granulated sugar until the mixture looks smooth and fluffy.
- Add the eggs: Beat in the eggs until combined.
- Add the vanilla: Mix in the vanilla extract.
- Add the dry ingredients: Mix the dry ingredients into the wet ingredients just until you don’t see dry flour.
- Fold in the chocolate chips: If using, fold in the chocolate chips until evenly mixed.
- Spread the batter: Spread the batter evenly in the prepared pan. Smooth the top into an even layer.
- Bake: Bake for 18 to 22 minutes, until the edges are set and lightly golden and the center looks just set.
- Cool: Cool completely in the pan.
- Slice: Lift the slab out using the parchment, then slice into bars.
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 them. Pull the pan when the edges look set and lightly golden and the center looks just set. If you wait until the center looks fully firm, the bars will bake up drier.
Chill the batter if it feels too soft. If your butter was very soft or your kitchen is warm, chilling the batter about 20 minutes helps it spread more evenly in the pan and bake up thicker.
Use parchment paper. It makes lifting and slicing so much easier, and it also helps keep the edges from sticking.
Pick the peanut butter you like. Creamy gives the smoothest texture, but crunchy is great if you want more bite. I usually avoid natural peanut butter here since it can make the texture a little unpredictable.
Watch the corners. The corners bake faster than the center in a 9×13. If your oven runs hot, start checking a couple minutes early.
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 cookie bars. This is especially good if you add a little flaky salt on top.
- Coffee: These are really good with coffee, especially dark roast or a latte. The peanut butter flavor holds up well next to coffee.
- Ice cream: Serve a bar with vanilla ice cream on the side. If the bars are room temp, I’ll warm one for a few seconds first.
- Fruit: Fresh berries are nice if you want something lighter on the plate. Strawberries and raspberries are both good with peanut butter and chocolate.
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 bars in an airtight container for up to 4 days. I usually keep them at room temperature so they stay soft and chewy.
If you want a firmer bar for cleaner slicing, you can chill them for a bit before cutting. Once they’re sliced, you can stack them with a piece of parchment between layers.
If you want them to last longer, freeze the bars for up to 2 months. I like freezing individual squares so I can grab one at a time.
Thaw at room temperature for about 30 to 60 minutes, or in the fridge overnight. If you like them warm, a quick microwave warm-up works fine.
A few quick answers
This section covers a few extra details that may help before you head to the recipe card.
Recipe FAQs
Can I use crunchy peanut butter instead of creamy?
Yes. Crunchy peanut butter works well and gives the bars little bits of texture throughout. The baking time stays about the same.
How do I know when the bars are done?
The edges should look set and lightly golden, and the center should look just set (not wet and shiny). They’ll firm up as they cool, so don’t wait for the center to look completely firm in the oven.
Can I skip the chocolate chips?
Definitely. They’re great as plain peanut butter cookie bars. If you still want a little crunch, chopped peanuts or peanut butter chips are both good swaps.
My batter seems really soft. Is that normal?
It can happen if the butter is very soft or your kitchen is warm. Chill the batter for about 20 minutes, then spread it in the pan—it will be easier to handle and bake up thicker.
Can I bake this in a different pan size?
A 9×13 is the easiest for this recipe. If you bake it in a smaller pan, the bars will be thicker and will need more time; a larger pan will make thinner bars that bake faster.
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
Soft Peanut Butter Cookie Bars
INGREDIENTS
Dry Ingredients
- 2 cups all purpose flour
- 1 tsp baking soda
- 1 tsp baking powder
- 1 tsp cornstarch
- 1 tsp fine salt.
Wet Ingredients
- 1 cup creamy peanut butter
- 1 cup packed light brown sugar
- 1/2 cup granulated sugar
- 1/2 cup unsalted butter softened
- 2 large eggs room temperature
- 2 tsp vanilla extract.
Optional Mix Ins
- 1 cup semi sweet chocolate chips
- flaky salt for topping.
INSTRUCTIONS
Prep
- heat oven to 350 F
- line a 9x13 inch baking pan with parchment and lightly grease
- whisk flour baking soda baking powder cornstarch and salt.
Mix And Bake
- beat butter peanut butter brown sugar and granulated sugar until smooth and fluffy
- beat in eggs then vanilla until combined
- mix in dry ingredients just until no dry flour remains
- fold in chocolate chips if using
- spread batter evenly in pan
- bake until edges are set and lightly golden and center looks just set 18 to 22 minutes
- cool completely in pan then lift out and slice into bars.
