Preheat your oven to 350F. You also want to move through this recipe pretty quickly so you don't give your eggs a chance to scramble in a relatively warm batter. So I would highly recommend measuring out all of your ingredients in advance so you are ready to add them as you need to.

In a cast iron skillet over medium heat, brown your butter, stirring frequently. The butter will melt, then bubble, and then foam. You'll be able to see your foam darkening in color as you stir, once the milk solids start to brown.

Remove from heat.

Once your butter is brown, whisk in your brown sugar and granulated sugar. Continue to mix until combined. It's okay if there's a little bit of butter that is not mixed in, but you want it as cohesive as possible.

Stir in the ice cube to cool down the mixture. You want to cool this down so when you add your eggs, they do not scramble. You want to move quickly from this point on, so as I mentioned in step 1, I would recommend that you have all of your ingredients ready. If you haven't done that yet, do it now!

Add your vanilla extract and whisked eggs. Quickly whisk this into your batter to incorporate.

As soon as the eggs are mostly incorporated, add your dry ingredients. Whisk until you have a cohesive batter.

Sprinkle your chocolate chips evenly over top of the cookie and quickly stir them in. They will start to melt pretty quickly, giving you nice swirls of chocolate in your final cookie. Top with a few more chocolate chips.

Bake at 350F for about 25 minutes. The edges and top should be set, but when you move the pan, the cookie should jiggle a little. You want that center to be very gooey.

Remove from the oven and top with ice cream. Enjoy!

The leftovers are equally delicious. The cookie will set up more as it cools. You will be able to slice it and have it later.