Chocolate Chip Cookie Bars (In 9 x 13 Pan)

If you’re hunting for the perfect ooey-gooey chocolate chip cookie bars, the hunt ends with this recipe. In a 9” x 13” pan, you can make the tastiest cookie bars full of chocolate, brown butter, and the perfect touch of flakey sea salt.

This chocolate chip cookie bar recipe is so easy and saves the extra effort of making individual cookies. Making the chocolate chip cookie bars in a 9” x 13” pan allows you to easily slice up 24 perfectly sized cookie bars. 

Not only are these cookie bars easy to make, but they’re unbelievably delicious.

This is because of the generous amount of chocolate chips, the nuttiness from brown butter, and the salty crunch from the flakey sea salt thrown on top.

What You'll Learn In This Recipe

Unsalted butter: Butter and other forms of fats are used in baking to add richness, flavor, and moisture. Butter helps baked goods have that nice soft and tender bite that makes them so enjoyable. 

If you use salted butter instead, be sure you adjust the fine sea salt in the recipe. 

All purpose flour: Flour is responsible for the texture and structure of the cookies. Make sure you are measuring your flour properly if you're not using a digital food scale. To properly measure your flour without a scale:

1. Fluff up the flour using a spoon.
2. Scoop the flour into the measuring cup.
3. Level off the measuring cup with a knife to remove any excess flour.

If you are looking to make this cookie recipe gluten-free, opt for a 1-to-1 gluten-free baking flour like Bob’s Red Mill. 

Fine sea salt: Salt is needed in all types of food, baking being no exception. Salt is a flavor enhancer, meaning that by adding salt, all the other ingredients involved will have increased flavor. When it comes to baking things like cookies, I prefer fine sea salt because it distributes more evenly throughout the dough.

Baking soda: This is the leavener that helps the cookies rise and achieve that light and airy texture. 

Granulated sugar: The sugar included in this recipe helps sweeten and tenderize the cookies. When the sugar is creamed with the butter, it also works to leaven the cookies. 

Light brown sugar: Brown sugar is a type of sugar with molasses added to it. This helps the cookies have a soft, chewy bite, with an added bit of deeper flavor. 

Eggs: Eggs hold everything together in cookies. They provide the structure that gives the cookies form. For this recipe, there is no need to wait for the eggs to come to room temperature. 

Vanilla Extract: Just a small amount of vanilla extract goes a long way in this recipe. This helps add an added depth of flavor to the chocolate chip cookie bars. 

Semi-sweet chocolate morsels: All good cookie recipes need that mix-in that brings it to the next level. Semi-sweet chocolate morsels are the perfect add-in for that yummy chocolate flavor and added texture. If you aren’t as big of a fan of chocolate, feel free to use 1 less cup of chocolate morsels in the recipe. 

Maldon sea salt flakes: This is the perfect finish for these sweet cookies. It really helps balance out the flavor as well as add a nice visual appeal to your cookie bars.

Before you get to work, heat your oven to 350°F (175°C) so it's hot and ready to go by the time you finish making the cookie bars. 

Next, line a 9 x 13 inch (23 cm x 33 cm) metal baking pan with parchment paper.

The easiest way to do this is by lightly greasing the entire inside of the pan. Then, grab a sheet of parchment paper and lay it underneath the pan.

Make sure the parchment paper is tall enough to leave a little overhang on the sides of the pan. If there's a lot of excess parchment, trim some of it off.

Then, place the parchment in the pan and fold one flap behind the other to create a tight corner. Use your fingers to fold and crease the sides of the parchment so it fits nicely along the side of the pan.

Set the pan aside while we move along to the next step.

The first step in the cooking process is browning your butter. Essentially, browning your butter is just cooking your butter on medium-high heat until it reaches a nice brown color. Be sure to whisk or stir constantly to avoid any burning. 

When it is ready, you should smell a nutty flavor and see some golden-brown specks at the bottom of the butter. After you see this, turn off the heat and transfer your browned butter into a heat-proof container to stop the cooking process and fully cool.

You can do this step ahead of time and store the browned butter in your fridge. Just be sure to let it soften to room temperature before using it in your cookie bar recipe.

If you’ve never made brown butter before, check out this 60-second video guide on how to make brown butter. 

Let's move on to make the cookie dough.

Mix the flour, salt, and baking soda together until they’re combined. Then, set this aside for a minute. 

Separately, beat the cooled brown butter, granulated sugar, and light brown sugar in the bowl of a stand mixer fitted with a paddle attachment.

Beat this on medium-high speed for about three minutes until it's light and fluffy. Beating the butter and sugar for a full 3 minutes is crucial for making your cookies lighter and fluffier. 

For this step, you can also use an electric hand mixer. 

Next, add in the eggs and vanilla and mix until everything is combined. 

Gradually add the flour mixture one cup at a time. After adding your last bit of flour, let it combine into the dough, and then shut off the mixer.

It is best if you mix the dough as little as possible in this stage to reduce how firm your cookie will be. Overmixing the dough will develop stronger gluten structures and therefore make the cookie bars more firm in texture. 

For the last step in the cookie dough, mix in your chocolate morsels by hand using a silicone spatula. The chocolate is added by hand, so the chips don’t break apart while in the mixer, and so we don't overmix the dough. 

The last part of this chocolate chip cookie bar recipe is to transfer the dough and bake it. For this, move your dough from the bowl and into the prepared baking pan.

For the most even bake on your cookies, push the dough, so it’s as level as possible. A useful trick for this is to take the leftover butter wrapper to push the cookie dough flat, that way your hands won't get dirty. 

Finally, bake the cookies for 26 - 30 minutes until they are lightly browned on top. At this point, the cookies will be soft and gooey in texture.

If you prefer a more well-done cookie, let them cook in the oven a little while longer until they have a more golden-brown complexion on top. 

Once the cookies are baked to perfection, remove the baking tray from the oven, and set it on a wire cooling rack. Sprinkle the cookie bars with Maldon sea salt flakes immediately after they come out of the oven to ensure that the salt sticks to the cookies. 

Let your chocolate chip cookie bars cool for at least 60 minutes. After they’ve cooled, remove the cookie bars from the pan, and slice them into 24 even squares (3 slices length-wise, and 8 slices width-wise).