Combine the flour, cocoa powder, baking soda, and sea salt in a mixing bowl and stir well to combine. Set aside until ready to use.

Add the eggs, granulated sugar, and vanilla extract to the bowl of a stand mixer fitted with the whisk attachment. Note: If you don’t have a stand mixer, you can use a large bowl and a handheld electric mixer.

Whisk the eggs and sugar together for 5 minutes on high speed. Be sure to go the full 5 minutes to whip enough air into the eggs. This process is what gives us the light texture and crackly top, so it’s an important one! Stick on a podcast or put some clean dishes away and I promise you, the 5 minutes will be worth it!

While the eggs and sugar are whisking away in the mixer, melt the chocolate. To do so, add the butter and chocolate chips to a microwave-safe bowl and microwave for 20 second increments, stirring between each interval, until melted, about 60 to 80 seconds total. You can also use a double boiler for this process.

Transfer the melted chocolate mixture to the mixer with the egg mixture and mix on low speed until all of the wet ingredients are combined.

Add the flour mixture to the stand mixer and beat on low speed using the paddle attachment or mix in by hand using a rubber spatula (I mix the dry ingredients in by hand).

Bake cookies on the center racks of the preheated oven for 9-10 minutes. I find 9 minutes is perfect for these fudgy chocolate brownie cookies.

Remove the cookies from the oven and allow them to cool on the cookie sheets for 10 minutes before transferring them to a wire rack to finish cooling.

Enjoy!

Store cookies in an airtight container or in a zip lock bag for up to 3 days on the counter, up to 5 days in the refrigerator, or up to 3 months in the freezer.