To make the heat treated flour: preheat the oven to 350°F. Spread 1 cup of all purpose flour on a parchment lined baking sheet. Bake for 5-7 minutes or until the flour registers 160°F on an instant read thermometer. Let cool completely before using. Sometimes heat treated flour will get clumpy, so be sure to sift it before using!
Using a stand mixer fitted with the paddle attachment, or a large bowl and hand mixer, cream together the room temperature brown butter, brown sugar, granulated sugar, salt, and vanilla until light and fluffy (3-4 minutes).
Add in the flour and milk and mix until just combined. If the dough is too dry, you can add in more milk 1 teaspoon at a time until the dough comes together.
Fold in the chocolate chips and enjoy!
Store the cookie dough in an airtight container in the fridge for up to a week or freeze in balls for up to 3 months. The butter in the dough will harden in the fridge, so you may need to let it sit out for a few minutes before it's easily scoopable.
If the cookie dough starts to dry out, just add in a bit more milk!
Notes
To make brown butter, melt unsalted butter over medium heat, stirring frequently. Watch closely for the butter to develop brown specs and a nutty aroma. Once you start seeing brown specs, let cook for just a few seconds longer (watch very carefully or it will burn). Remove from the heat and pour into a small bowl so that it doesn't continue to cook .Set aside and let cool for about 20 minutes in the fridge until soft and pliable. Note: For every ½ cup (1 stick or 113g), you'll lose about 1 tablespoon (14g) to evaporation while cooking. So you can either add in an extra 1 tablespoon before browning, or if you're browning big batches, just make up the weight difference in your recipe with regular unsalted butter if needed.