PB & J Blondie Bars with Marshmallow Meringue

We’ve all had a PB & J. And we’ve all had a fudgy blondie. But have we mashed them together and put fluffy marshmallow meringue on top? I did! And it was the right decision because holy cow these PB & J Blondie Bars with Marshmallow Meringue are to die for. They’re sweet, salty, fudgy, and slightly tart from the strawberry jam. They’re everything we love about a nostalgic childhood favorite like a PB & J, but about a zillion times better.

PB & J Blondie Bar Ingredients

• Peanut Butter. You’re gonna want to use a classic creamy (or crunchy!) peanut butter – think JIF – for this recipe, not one that requires you to stir the separated oil back in.
• Strawberry Jam. For these peanut butter bars I used the jarred strawberry preserves from Trader Joe’s. But, if you have some strawberries you want to use up, I’ve got a quick strawberry jam recipe in this post that’s easy and delicious.
• Egg Whites. The fluffy homemade marshmallow meringue that sits on top of these bars is simple to make and requires egg whites. Don’t worry, they get fully cooked with the sugar before you whip them into meringue. I recommend using fresh egg whites rather than egg whites in a carton or an egg white substitute.

How to Make PB & J Blondie Bars

Make the peanut butter blondie dough.

This recipe can be whipped up in a stand mixer, or in just a large bowl with a whisk. For the dough, I just did it in a regular bowl with a whisk. Start by whisking the sugar, brown sugar, and melted butter until well combined and smooth. Whisk in the peanut butter, followed by the eggs and vanilla.

Switch to a rubber spatula and fold in the flour and baking powder. I didn’t add any extra salt to the dough because I used salted butter and the peanut butter is salty as well. If you use unsalted butter, add about a 1/2 tsp of salt. Press the dough into a parchment lined 8″ square pan. Bake at 350 for 22-24 minutes. The bars will still look a little wet in the center, but will set up as they cool. Let the bars cool completely while you whip up the marshmallow meringue.

Make the marshmallow meringue.

In a double boiler, or a glass bowl over a saucepan with a couple inches of water, add the sugar and egg whites. Cook over medium heat until the mixture becomes opaque and the sugar is dissolved. You can test this by rubbing a bit of the mixture between your fingertips. If it still has grit to it, keep cooking. Once it’s completely smooth, remove it from the heat.

Pour the egg white mixture into the bowl of your stand mixer with the whisk attachment. Whip on medium high speed until it form stiff peaks. Whisk in the vanilla until combined. Spread the meringue onto the cooled peanut butter blondie bars. Dollop TBSP sized scoops of the strawberry jam all over the meringue and use a small spoon, butterknife, or skewer to swirl the jam into the meringue. Use a kitchen torch to toast the meringue.

Use the parchment paper to life the bars out of the pan. You might need to run a sharp knife along to edges to make sure it releases easily. Slice into 16 bars. For clean edges, make sure to wipe off the knife between cuts.

Tools needed to make these PB & J Blondie Bars

1. Stand Mixer or Electric Hand Mixer for the meringue. Trust me, you don’t want to try to whip it by hand.
2. Kitchen Torch. A small kitchen torch is the best way to get the perfect golden brown torch on the marshmallow meringue.
3. 8″ Square Baking Pan. My favorite baking pans are from USA Pan. Really can’t beat ’em. I used this one in this recipe.
4. Double Boiler. OR just a glass bowl that will fit on top of a saucepan filled with a few inches of water to cook the egg whites and sugar.
5. Kitchen Scale. This is me begging you to get a kitchen scale to weigh your ingredients. I know I say it every time, but it’s the only way to make sure your bake turns out exactly like mine. It’s SO EASY to overpack your flour and get dry cookies, bars, and cakes.

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Frequently Asked Questions

1. Can I make these gluten free? Although I haven’t tested it, you should be able to swap out the All Purpose Flour for a gluten free 1 to 1 flour replacement with no issues!
2. I don’t like strawberry jam. What could I use instead? If strawberry jam isn’t your…. well, jam – swap it out for raspberry jam, blackberry preserves, or really throw it back to childhood pb&j’s with grape jelly!
3. My meringue isn’t whipping to stiff peaks. How do I fix it? If you have trouble with your marshmallow meringue and just can’t seem to get it to whip up there could be a couple issues. Meringue hates fat. So if there was even a trace of butter or oil in your bowl before you started whipping, you’ll have trouble. Another thing to try to stabilize your meringue is adding a pinch of cream of tartar to the egg white/sugar mixture after it has been cooked, but before you start mixing.

If you loved this recipe for PB & J Blondie Bars with Marshmallow Meringue, be sure to tag @buuckfarmsbakery on Instagram and leave a star rating and review below! If you want to pin this recipe for later, click the button in the recipe card or any photo in this post.

For more of my dessert bars, check out these recipes –

• Dark Chocolate Sugar Cookie Bars
• Lemon Blueberry Shortbread Bars
• S’mores Rice Krispie Treats
• No Bake Almond Butter Cheesecake Bars
• Gluten Free Chocolate Chip Cookie Bars