Heat-Treat the Flour: Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper. Spread the flour evenly over the pan. Bake for 6-8 minutes, or until the flour reaches a temperature of 160°F (70°C). Let the flour cool completely before using it in the dough. If the flour clumps up after baking, sift it into the dough to ensure a smooth texture.
Cream the Butter and Sugar: In a large mixing bowl, use an electric mixer or stand mixer to cream together the brown sugar, granulated sugar, and butter. Beat the mixture until it becomes light and fluffy, about 1 minute. Add the vanilla extract and salt, and mix until well combined.
Combine Dry Ingredients: Gradually beat the heat-treated flour into the butter and sugar mixture until just combined. Add the milk one tablespoon at a time, beating until the dough starts to come together. Gently fold in the miniature chocolate chips using a rubber spatula.
Serve and Store: Enjoy the cookie dough immediately or store it in an airtight container in the refrigerator for up to one week. For longer storage, freeze the dough for up to three months. When ready to eat, thaw in the refrigerator overnight and let it sit at room temperature for a few minutes to soften slightly before serving.