Peanut Butter Sugar Bars are my kind of easy dessert bar: soft and chewy, simple, and very peanut-butter-forward. They’re basically a sugar cookie bar with that familiar peanut butter depth, and I like how they slice cleanly for sharing.
The best part is the thick peanut butter glaze on top. It sets up just enough to hold its shape, but it still tastes like peanut butter frosting, which is exactly what I want on a bar like this.
I make these when I need something dependable for a cookie tray, a casual get-together, or just a weekend bake. They’re also one of those bars that travels well, which makes them great for bake sales and potlucks.
Why You’ll Love This Recipe
Soft and Chewy: The centers stay tender and the edges get just a little more set, like the best kind of cookie bar.
Big Peanut Butter Flavor: Peanut butter is in the batter and the glaze, so it actually tastes like peanut butter bars (not just “sweet bars”).
Easy to Slice and Share: A 9×13 pan gives you plenty of servings, and they cut into neat squares once the glaze sets.
Glaze Makes Them Special: The peanut butter glaze is quick, but it makes the bars look finished and adds that extra creamy layer.
Good for Add-Ins: Chocolate chips or chopped peanuts fit right in if you want a little texture or extra richness.
Ingredients You’ll Need
Bar Batter
- Unsalted butter: I like using softened butter so it creams easily with the peanut butter. If it’s too warm and greasy, the bars can bake up a little flatter.
- Creamy peanut butter: Regular creamy peanut butter (like the classic shelf-stable kind) is the most consistent here. Natural can work, but it needs to be really well stirred and not super oily.
- Granulated sugar: This gives that classic sugar-cookie sweetness and helps the top get lightly crackly.
- Light brown sugar: Brown sugar is where a lot of the chew comes from. Dark brown sugar works too if that’s what you have.
- Eggs: Use large eggs. They help the bars set up while still staying soft in the middle.
- Vanilla extract: Don’t skip it. It helps the bars taste more like a cookie bar and less like plain peanut butter.
- All-purpose flour: I use regular all-purpose flour here. Spoon and level if you tend to pack flour into the cup.
- Baking powder: This gives a little lift so the bars aren’t dense.
- Baking soda: Helps with browning and keeps the texture tender.
- Fine salt: Peanut butter needs salt to taste like peanut butter. Fine salt blends in evenly.
- Nonstick spray or butter: Grease the pan well, especially the corners. Parchment is even better if you want easy lifting and cleaner slices.
Peanut Butter Glaze
- Unsalted butter: Melted butter makes the glaze smooth and easy to spread.
- Creamy peanut butter: This is what gives the glaze that peanut butter “frosting” feel. I stick with creamy for the smoothest top.
- Powdered sugar: This thickens the glaze fast. If your powdered sugar is lumpy, sift it, or whisk a little longer.
- Milk: Use just enough to get a thick, spreadable glaze. Any milk you keep in the fridge is fine.
- Vanilla extract: A small amount makes the glaze taste less flat.
- Salt: Just a pinch keeps the glaze from tasting too sweet.
Recipe Instructions
- Preheat the oven: Heat the oven to 350°F. Grease a 9×13-inch pan with nonstick spray or butter (or line with parchment, then grease lightly).
- Beat the butter and peanut butter: In a large bowl, beat the softened butter and peanut butter until smooth and fully combined.
- Add the sugars: Beat in the granulated sugar and brown sugar until the mixture looks lighter and fluffy.
- Add the eggs and vanilla: Mix in the eggs, then the vanilla, and beat just until everything is combined.
- Mix the dry ingredients: In a separate bowl, whisk the flour, baking powder, baking soda, and salt together.
- Add the dry ingredients: Stir the dry ingredients into the wet mixture just until you don’t see dry flour anymore. Don’t overmix.
- Spread the batter: Spread the batter evenly in the prepared pan. Smooth the top so it bakes evenly.
- Bake: Bake for about 18 to 22 minutes, until the edges are set and a toothpick comes out with a few moist crumbs.
- Cool: Cool the bars completely in the pan before adding the glaze.
- Make the glaze: Whisk the melted butter and peanut butter until smooth. Whisk in the powdered sugar, vanilla, salt, and enough milk to make a thick, spreadable glaze.
- Glaze the bars: Spread the glaze over the cooled bars in an even layer. Let it set at room temperature.
- Slice and serve: Cut into bars and serve right away, or wait until the glaze firms up a bit more for cleaner slices.
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 the center still looks a little soft. They’ll keep baking from the heat of the pan as they cool.
Use parchment paper if you can. A parchment sling makes it easy to lift the whole thing out and slice on a cutting board. It also helps if you like really clean edges.
Watch the butter temperature. If your butter is very soft and shiny, the batter can feel looser than usual. If that happens, the bars still work, but they may bake up a little thinner.
Mix just until combined. Once the flour goes in, stop mixing as soon as you don’t see dry spots. Overmixing makes the bars bake up tougher.
Keep the glaze thick. Start with less milk and add a little at a time. A thicker glaze is easier to spread without running, and it sets nicer on top.
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 these. It’s especially nice if you cut the bars on the smaller side.
- Coffee: I like these with black coffee or a latte. The peanut butter and brown sugar combo goes really well with coffee.
- Ice cream: Serve a bar with a scoop of vanilla ice cream if you want to make it more of a plated dessert. A little chocolate sauce on top is good too.
- Fruit: Fresh berries are a nice side if you want something lighter on the plate. Strawberries and raspberries both work well here.
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 airtight at room temperature for up to 5 days. I keep them in a single layer when I can, but you can stack them with parchment between layers.
If you want to make this recipe ahead, you can bake the bars the day before and glaze them once they’re fully cooled. The glaze sets nicely at room temperature, so they’re easy to transport.
For longer storage, freeze the bars for up to 2 months. I like freezing them already sliced so you can grab one or two at a time.
Thaw at room temperature for an hour or two, or overnight in the fridge. The glaze will soften a bit as it thaws, but it firms back up once it sits out.
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 sugar bars are done?
Look for set, lightly golden edges and a center that doesn’t look wet. A toothpick should come out with a few moist crumbs, not clean.
Can I use natural peanut butter?
You can, but it needs to be well stirred and not overly oily. If it’s separated or very runny, the batter can change texture and the bars may bake up a little different.
Can I add chocolate chips or peanuts?
Yes. I like adding about 1 cup chocolate chips for a sweeter bar, or about 1/2 cup chopped peanuts if you want some crunch.
Why did my glaze turn out too thick or too thin?
If it’s too thick, whisk in a tiny splash more milk until it spreads easily. If it’s too thin, add a bit more powdered sugar and give it a minute or two to thicken as it sits.
Can I freeze these bars?
Yes, they freeze well. Freeze them sliced in an airtight container, then thaw at room temperature or in the fridge.
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
Peanut Butter Sugar Bars
INGREDIENTS
Bar Batter
- 1 cup unsalted butter softened
- 1 cup creamy peanut butter
- 1 cup granulated sugar
- 1 cup packed light brown sugar
- 2 large eggs
- 2 tsp vanilla extract
- 2 cups all purpose flour
- 1 tsp baking powder
- 1 tsp baking soda
- 1/2 tsp fine salt
- nonstick spray or butter for pan.
Peanut Butter Glaze
- 2 tbsp unsalted butter melted
- 1/3 cup creamy peanut butter
- 2 cups powdered sugar
- 3 tbsp milk
- 1 tsp vanilla extract
- pinch of salt.
INSTRUCTIONS
Bake Bars
- Heat oven to 350 F and grease a 9x13 inch pan
- Beat butter and peanut butter until smooth then beat in sugars until fluffy
- Mix in eggs and vanilla until combined
- Whisk flour baking powder baking soda and salt then stir into wet mixture just until no dry flour remains
- Spread batter evenly in pan and bake until edges are set and a toothpick comes out with a few moist crumbs
- Cool completely in pan before glazing.
Glaze and Serve
- Whisk melted butter and peanut butter until smooth then whisk in powdered sugar vanilla salt and enough milk for a thick spreadable glaze
- Spread glaze over cooled bars and let set at room temperature
- Slice into bars and serve.
