Brown the butter. Do this by adding the butter to a saucepan over medium heat. letting it melt, then foam, then when the liquid becomes brown underneath the bubbles and brown flecks appear, it’s done! Remove from heat. 

Let the butter cool to room temp, at least 30 minutes or longer.

Prepare one cup of sourdough discard. (Notes above on how to make discard).

Combine the browned butter and both sugars. Beat together with an electric hand mixer or with a stand mixer. The mixture will look a bit dry and crumbly, like semi- wet sand. 

Add the egg yolk to the mixture and beat with an electric mixer for a couple of minutes. As you continue beating, the mixture will become lighter and fluffier.

Add the sourdough discard and beat together until just barely combined. The dough will look more like cake batter than cookie dough. don’t fret.

Add the salt, baking soda, baking powder and vanilla. Mix until combined.

Add the flour and mix together by hand until just barely combined, being careful not to overmix.

Add the chocolate chips and mix together by hand.

Test the dough. *see note above* This is an optional step, but helps you to prevent cookies from coming out flat. Bake one, 1/4 cup sized ball of dough at 350 for 12-13 minutes. Depending on you elevation and the weather outside, the cookie dough texture can vary a bit. Testing one dough ball allows you to see if the cookie comes out well. If it is too flat, then the dough needs about 1/4 cup more flour. If it is just right, then leave it be and continue on to the next step.  

Cover the bowl of dough with plastic or a lid, and refrigerate. OR, roll into balls and transfer to an air tight container and refrigerate. Let the dough stay in the refrigerator to ferment for anywhere from one hour to seventy-two hours. I usually aim for about 4 hours. The longer it sits in the fridge, the more fermentation will happen and the more sour the cookies will taste. 

Preheat your oven to 350 degrees.

Prepare a baking sheet by lining it with parchment paper*. 

Remove the dough from the fridge and scoop in to smooth 1/4 cup balls if you haven’t already. Place six dough balls on each baking sheet. Top the dough balls with a few more chocolate chips.

Bake the dough balls for 13-14 minutes, or until edges just begin to brown. 

Remove from oven, and place {even more} chocolate chips on the top of each cookie…. just to make it look pretty. Then sprinkle the cookies with some coarse sea salt flakes.* (Honestly… don’t skip this! It’s so good!) 

Let cookies cool on a cooling rack. Serve immediately, and freeze any leftovers! 

ENJOY!