Cube the butter and In a small sauce pan, heat the butter on medium heat. The goal is to brown the butter, not burn it, so stir periodically and keep an eye on it. It should take 3-7 minutes, but it could take longer. Remove from heat when the milk solids in the melted butter turn a light brown. Set aside your brown butter to cool.

In a bowl, whisk the flour, salt, and baking soda together very well. If you don’t, you could end up with baking soda “land mines” in your cookies and you don’t want that. Trust me. 

Using a stand mixer or hand mixer and in a separate mixing bowl, mix both sugars, miso, vanilla, and butter. After those ingredients are incorporated, mix the eggs in one at a time on medium until the batter looks like caramel. 

Reduce the speed to low and gradually add the dry ingredients (flour, salt, making soda mixture) until they are just incorporated.

Fold the chocolate into the dough.

On a baking sheet, scoop balls of cookie dough, about the size of a golf ball or ping pong ball, and place them about an inch apart. You likely won’t fill the tray with all of the dough, so refrigerate the remaining dough and place the tray of prepared cookie dough in the freezer to chill for a few minutes. 

Meanwhile, set your oven to preheat to 375 degrees F. Once preheated, remove the tray of cookie dough balls from the freezer and place in the oven for 12 minutes. After baking for 12 minutes, check to see if the cookies have browned any. If you notice browning, pull them out of the oven and let them cool on the tray for about two minutes. Then transfer with a spatula to a cooling rack. The cookies will be really soft, like fall apart soft, when they come out of the oven, but they will harden as they cool to create a really nice soft cookie. Repeat the steps with the remaining dough. The dough will refrigerate well for up to a few days if you want to wait to bake the rest later.