My mother-in-law brought peanut butter bars to a barbecue years ago and refused to write the recipe down. Turns out there wasn’t much to write. Five ingredients, one bowl, and no oven at all.
These are the peanut butter bars with chocolate on top that turn up at every school fundraiser and church potluck in America. People compare them to Reese’s cups. That’s fair, though I think these are better cold.
Below, you’ll find a brownie version for when you do want the oven on. After that there’s a handful of quick desserts and a lighter oat batch that skips the powdered sugar.
Why You’ll Love This Recipe
Peanut butter bars take ten minutes of actual work. Melt, stir, press into a pan, then pour the chocolate over the top. The fridge does everything else while you get on with your evening.
Nothing can burn here. There’s no oven involved, no timer to watch, and no way at all to overbake something that never goes into an oven in the first place.
They also cut cleanly, which sounds minor until you’ve tried slicing a chilled slab of solid chocolate. There’s a trick for that, and it lives in the topping rather than the base.
Peanut Butter Bars Ingredients & Substitutions
Five things, that’s all. Buy graham cracker crumbs in a box if your shop sells them, because hand-crushed crackers leave chunks that make the base crumble the moment you cut it.
| Ingredients | Amount | Substitution or Note |
| Unsalted butter | 1 cup (226 g), melted | Salted butter, then skip the added salt |
| Creamy peanut butter | 1¼ cups (320 g), divided | Not natural style |
| Powdered sugar | 2 cups (240 g) | Sifted, no swaps here |
| Graham cracker crumbs | 2 cups (200 g) | Digestive biscuits or Ritz |
| Fine salt | ¼ teaspoon | Balances the sweetness |
| Chocolate chips | 1½ cups (255 g) | Semisweet or milk |
- Use regular peanut butter, the kind that doesn’t separate. Natural jars are too oily here and the base won’t set firm in the fridge.
- Powdered sugar is doing structural work, not just sweetening. Granulated sugar stays gritty and the bars never hold together properly.
- That ¼ cup of peanut butter in the topping is the whole trick. It keeps the chocolate soft enough to slice instead of shattering.
- Fine crumbs, please. Big graham shards create weak spots, and the bars break along them every time.
How To Make Peanut Butter Bars
Step 1: Mix the Base
- Melt the butter and 1 cup of the peanut butter together, either in a saucepan on low or in the microwave in 30 second bursts.
- Stir in the powdered sugar and salt first, then add the graham cracker crumbs one cup at a time until you have a thick dough.
Step 2: Press It Into the Pan
- Line a 9×13 pan with parchment, leaving an overhang on two sides so you can lift the whole slab out later.
- Press the mixture in firmly and flatten the top with the back of a spoon, then chill for 15 minutes.
Step 3: Make the Chocolate Layer
- Melt the chocolate chips with the remaining ¼ cup of peanut butter, stirring every 30 seconds until smooth.
- Pour it over the chilled base and spread it right to the corners before it starts to set.
Step 4: Chill and Cut
- Refrigerate for at least 1 hour, or 2 if your fridge runs warm.
- Score the chocolate into squares while it’s still slightly soft, then cut through fully once set.
Peanut Butter Brownies
Sometimes I want the oven on. Peanut butter brownies give you a fudgy chocolate base with peanut butter swirled through the top, and they bake in a small pan, so the batch is manageable.
What You Need
- ½ cup melted butter
- 1 cup sugar
- 2 eggs
- 1 teaspoon vanilla
- ⅓ cup cocoa powder
- ½ cup flour
- ¼ teaspoon salt
- ½ cup creamy peanut butter, warmed until pourable
How to Make Them
- Whisk the butter and sugar, then beat in the eggs and vanilla until the batter turns glossy.
- Stir in the cocoa, flour, and salt, and spread it into a lined 8×8 pan.
- Dollop the warm peanut butter over the top in spoonfuls, then drag a knife through it in an S shape.
- Bake at 350°F for 30 to 35 minutes, until the edges pull away slightly from the sides.
Let them cool all the way down before you cut them. Warm brownies smear badly, and the swirl you spent time on ends up disappearing onto the knife instead of staying on the brownie.
Easy Peanut Butter Desserts
When I don’t want to make anything at all, these are the easy peanut butter desserts I fall back on. None of them really need a recipe card, which is rather the point.
- Peanut butter cups: press the base mixture into mini muffin liners, top with melted chocolate, chill.
- Two ingredient fudge: melt a cup of chocolate chips into a cup of peanut butter, chill in a loaf tin.
- Frozen banana bites: sandwich peanut butter between banana slices, dip in chocolate, freeze.
- Apple dip: stir peanut butter with a spoonful of honey and a splash of hot water until pourable.
- Mug cake: peanut butter, an egg, a spoon of sugar, and 60 seconds in the microwave.
The fudge is the one I make most. It sets hard in about two hours and keeps in the fridge for a fortnight, though it never lasts that long here.
Healthy Peanut Butter Bars With Oatmeal
Healthy peanut butter bars are a genuinely different recipe, not a lighter version of the one above. Oats replace the graham crumbs and maple syrup does the sweetening, so no powdered sugar goes in at all.
- Stir 1½ cups rolled oats with 1 cup natural peanut butter, ⅓ cup maple syrup, and a pinch of salt.
- Press into a lined 8×8 pan, the same way as the base above.
- Melt ¾ cup dark chocolate over the top and chill for an hour.
Peanut butter bars with oatmeal come out chewier and a lot less sweet. Natural peanut butter works fine in this one, because the oats soak up the extra oil instead of sliding around in it.
They’re still a treat, to be clear. There’s still plenty of sugar in the maple syrup and the chocolate, so call it a better snack rather than anything close to a health food.
Pro Tips
- Let the pan sit out for 10 minutes before cutting. Cold chocolate cracks under a knife, and nobody wants a shattered top layer.
- Run your knife under hot water and wipe it dry between cuts. It costs thirty seconds and the edges come out sharp.
- Store the peanut butter bars in the fridge in a sealed container for up to a week. They go soft at room temperature within a couple of hours.
- Freeze the cut squares between sheets of parchment for up to 3 months. Ten minutes on the counter and they’re ready.
Wrapping Up
Make the peanut butter bars the day before you need them. The texture is better after a full night in the fridge, and the chocolate cuts more cleanly.
One warning, though. Twenty-four bars sounds like plenty right up until you cut the first one, and after that the pan empties a good deal faster than seems possible.
Peanut Butter Bars
Ingredients
Method
- Melt butter with 1 cup peanut butter
- Stir in powdered sugar, salt, and graham crumbs
- Press into a lined 9×13 pan
- Chill 15 minutes
- Melt chocolate with the rest of the peanut butter
- Spread over the top
- Chill 1 hour and cut
