Levain Bakery Signature Chocolate Chip Walnut Cookie Recipe

I love LEVAIN Bakery.  They are my rare treat and I've always wanted to try to make these "world famous, deliciously decadent cookies" on my own.  They were my post-marathon indulgence (I ate 4 - oatmeal chip, dark chocolate cookie, chocolate walnut and peanut butter) literally in one day.  I love these so much I don't trust myself to even go to their newest location mere blocks away on the Upper East Side.  So I made them myself.  I'll keep working on the recipe, but they came out prettyyy fine.  Next up: Levain's Oatmeal Chip. 

Ingredients 
1 cup (2 sticks!) Cold Butter cut into small cubes
1 cup Brown Sugar
1/2 cup Sugar
2 Eggs
1 1/2 cups Cake Flour - I used Bobs Red Mill Pastry Flour *
1 1/2 cups Flour
1 teaspoon Cornstarch
3/4 teaspoon Baking Soda
3/4 teaspoon Salt
2 cups Dark Chocolate Chips
1 package of your favorite milk chocolate bar, broken into piece (why not ya know) 
2 cups Walnuts roughly chopped

Instructions

• Preheat oven to 410 degrees.
• In a large mixing bowl - or better yet an electric mixer if you have one, cream together cold cubed butter, brown sugar, and sugar. Make sure it's blended well. Props to you if you can do this with your hand and a spoon, but an electric mixer will save the day. And your hands, so as to not limit your ability to eat these cookies. 
• Keep butter/sugar mix in the mixer (or bowl) and add eggs, one at a time, mixing well after each one.
• Stir in flours, cornstarch, baking soda, and salt. Mix until just combined to avoid overmixing. Stir in chocolate chips and walnuts.
• Separate dough into large balls and place on lightly colored cookie sheet. They are bigger than you think! You will fit 4 cookies on one large cookie sheet. The dough makes 8 extra large cookies.
• Bake for 9-12 minutes or until golden brown on the top. Let them rest for at least 10 minutes to set.

Notes: Chilling cookie dough for just 30 minutes makes a big difference.
I wrapped the remaining dough (I only made 5 cookies - at first, don't worry, I'm not insane) and kept the rest wrapped in Saran Wrap over night in the fridge. If you want to know why just 30 MINUTES of chilling makes for even better cookies, check out the below, pulled from trusted King Arthur Baking. 

"Why refrigerate chocolate chip cookie dough – or for that matter, any basic drop cookie dough – before baking? Does chilling cookie dough really make any difference?

The short answer: yes, chilling cookie dough prior to baking does make a difference.
1. Chilling cookie dough controls spread.
2. Chilling cookie dough concentrates flavor.
3. Chilling cookie dough changes texture.

Click here for the full details. 

*can substitute all-purpose flour for cake flour
​**Thank you Modern Honey for inspiring this recipe!