Brown 8 oz of Butter on medium high until the milk solids just start to brown and the butter color turns a medium amber color. Turn the heat to low and add Dried Milk Powder. Keep on low heat, stirring occasionally, until the whole butter mixture turns a deep brown. Turn the heat off and add your espresso powder into the browned butter mixture and stir.
Slowly add in the Heavy Cream. You don't want to add it in all at once or the thermal shock of the cold heavy cream and hot Browned butter will sizzle over and make a mess. Mix everything together to combine and store in the fridge until it reaches 64 degrees F.
Take your cold butter out of the fridge when you put your browned butter in the fridge so it can temper.
While the browned Butter cools, weigh out all your ingredients and chop your chocolate from whole blocks.
Combine all the dry ingredients together in a big bowl and stir them together to make the dry mixture even.
Once your Browned Butter is done cooling, add all of your sugars, Vanilla Extract, and butters together into your stand mixing bowl. Cream just your butter and sugars together until it whips smoothly together.
Then add your eggs into the bowl and whip on high speed until it gets fluffy and you develop some stiff peaks in the mixture.
First mix in Chocolate chunks with the Creamed butter to evenly distribute chocolate. Then add in all your dry ingredients to combine everything into a homogenous mixture.
Ball your cookie dough into 6 ounce chunks. Don't ball them up in a perfect ball, build them rustically and like a tower. Add large chocolate chunks on top of the shaped cookie dough.
Rest cookie dough balls for 2 days in the fridge.
Bake at 460 F on Convection for 7 minutes. Once finished, top with Flakey salt and let it sit and rest for at least 90 minutes.