Brown Butter Chocolate Chip Cookie Bars

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Few can resist a fudgy chocolate chip cookie bar, and adding the element of brown butter makes these ones DISAPPEAR. The brown butter creates rich, nutty caramel notes that make the flavor of these cookie bars so special. They’re thick and fudgy, loaded with chocolate chips, and are the perfect low-effort (yet big payoff!) dessert to bring to any gathering, any time of year. 

I used my chocolate chip cookie cake recipe as a starting point for these brown butter chocolate chip cookie bars and once I thoroughly tested them, I started taking them to summer gatherings and sent some of the batches to work with my husband. In all scenarios, these cookie bars were not only gone in minutes, but people could not stop talking about them! In other words, these cookie bars will make you a hero.  

Why You’ll Love these Cookie Bars

• Thick and fudgy. These are everything you want in a cookie bar texture. They bake up thick with a slightly crisp exterior, and the inside sets perfectly into a fudgy, chewy cookie bar that stays moist for days. 
• Low-effort (but big payoff). The only real effort with these is browning the butter, which can be done in about 5 minutes. After that, the dough comes together quickly, requires no time to chill, and bakes in less than 20 minutes, and yields the most incredible cookie bars everyone will rave about.
• Brown butter magic. Adding brown butter really levels up the flavor of these cookie bars! It adds a nutty, caramelized undertone that really enhances the average chocolate chip cookie flavor profile. 
• ALWAYS a hit. You can enjoy these warm and gooey with a scoop of vanilla ice cream, or let them set into the perfect fudgy-yet-sliceable cookie bar. Whip them up on a whim or make them up to 2 days ahead. In any case, these brown butter chocolate chip cookie bars will always be a hit. 

What Gives these Cookie Bars the Perfect Texture

This brown butter chocolate chip cookie bar recipe is pretty straightforward when it comes to cookie bar recipes, but there are a few key ingredients and baking techniques that make them stand out: 

• Melted brown butter. There’s no creaming butter and sugar together in this recipe. Instead, the brown butter is whisked together with the sugars at the beginning of the recipe. This technique gives the cookie bars a crisp, caramelized exterior while keeping the inside chewy and fudgy.
• Brown sugar + granulated sugar. A combination of these two sugars keeps the edges of these cookie bars crisp while keeping the center chewy. 
• Extra egg yolk. Adding an extra egg yolk adds moisture and richness to these cookie bars without adding the structural, drying proteins found in egg whites. This keeps the baked cookie bars moist and fudgy for days. 
• Cornstarch. A little bit of cornstarch thickens these cookie bars in the baking process, which yields a soft, bakery-style texture without being cakey. 
• Slightly underbake. You’ll want to bake these brown butter chocolate chip cookie bars until they’re evenly puffed and just starting to brown on the edges. They will continue to bake in the pan as they cool. This technique ensures that the cookie bars are the ideal texture once sliced. 

How to Brown Butter 

This recipe starts with browning unsalted butter, and even if you’ve never done it before I promise it’s not complicated. As long as you follow these steps and timing, you’ll be fine:

Step 1: Melt the butter. Add the butter into a skillet set over medium heat and allow it to melt while you stir it occasionally.

Step 2: Brown the butter. Continue to cook for 2-3 minutes while you stir constantly. The melted butter will start to foam on top, then the foam will subside before turning the butter light brown in color as the milk solids caramelize. It will smell deliciously nutty at this point. 

Step 3: Transfer the brown butter. As soon as you see the milk solids have turned light brown, transfer the brown butter to a heat proof container. It’s important to do this quickly so that the brown butter doesn’t burn. For this recipe, you’ll want the brown butter to cool for about 5-10 minutes before starting to make the cookie dough.

How to Make Brown Butter Chocolate Chip Cookie Bars

Brown the Butter. Melt 10 tablespoons of unsalted butter in a skillet, then cook over medium heat until the milk solids caramelize. Transfer to a glass container while you gather the rest of the ingredients.

Combine the Brown Butter and Sugars. In a medium bowl, add the brown and granulated sugars. Pour the brown butter on top and whisk together until combined.

Add the Egg, Egg yolk, and Vanilla. Whisk in the egg, egg yolk, and vanilla until combined. 

Fold in the Dry Ingredients. Add the baking soda, baking powder, cornstarch, salt, and all-purpose flour (no need to whisk together beforehand). Fold it together with the wet ingredients until a dough forms.

Fold in the Chocolate Chips. Reserve about ⅓ cup of the chocolate chips, then fold the rest into the dough. 

Press into the Pan and Bake. Press the dough into a greased and lined 8-inch square baking pan. Press the reserved chocolate chips into the top of the dough and bake at 350ºF for 17-20 minutes, until evenly puffed and the edges are just starting to brown.

Cool and Serve. Let the cookie bars cool in the pan for 30 minutes, then remove from the pan and continue cooling on a wire rack OR serve warm and gooey. 

More Recipes You’ll Love

If you love these brown butter chocolate chip cookie bars, here are some similar recipes from my blog to add to your baking list:

• Brown Butter Chocolate Chip Cookie Skillet
• Chocolate Chip Cookie Cake
• Strawberry Shortcake Cookie Bars
• Pumpkin Chocolate Chip Cookie Bars
• Sheet Pan Chocolate Chip Cookie Cake
• Sheet Pan Frosted Sugar Cookie Bars

I hope you love these brown butter chocolate chip cookie bars as much as I do! Let me know if you make it in the comments below (be sure to leave a star rating!) and feel free to tag @sugarandsparrowco on Instagram to show me if you post a photo. I love to see what you create with my recipes!