Step 1

Brown the butter: Melt the butter in a saucepan over medium heat. Continue cooking and stirring regularly until it foams and then turns golden brown and smells nutty. Remove from heat immediately.

Step 2

Heat treat the flour: Place flour in a microwave safe bowl and microwave for 2 minutes, then stir to remove any clumps. Alternatively, you can bake it. Preheat your oven to 350°F (175°C), spread the flour evenly on a baking sheet, and bake for 5 minutes or until the flour reaches 160°F (71°C). Let it cool completely.

Step 3

In a bowl, add the browned butter, brown sugar, white sugar, vanilla paste, salt, and 2 tablespoons of milk. Use a hand mixer to beat until the mixture is fluffy, about 3 minutes.

Step 4

Gradually add the heat-treated flour to the bowl, mixing until just combined. If the dough is too thick, add the remaining milk, a ½ tablespoon at a time (up to 1 tablespoon more if needed), until you reach the desired consistency.

Step 5

Using a rubber spatula, fold in both the semisweet and milk chocolate chips.

Step 6

Sprinkle with flaky sea salt if desired.

Step 7

Store the cookie dough in the refrigerator. It will harden once chilled as the butter solidifies. Let rest at room temperature before serving.

Step 8

Enjoy!