Heat treat the flour: Preheat the oven to 350°F. Line a baking sheet with parchment paper. Measure the flour and sprinkle it evenly on the pan. Bake it for 6-8 minutes, or until the flour temperature reaches 160°F. Allow the flour to cool before mixing it into the cookie dough. It may tends to clump up, so sift it into the dough for a smooth texture.
Cream the butter and sugar: In a large bowl using an electric mixer or stand mixer, cream together the brown sugar, granulated sugar, and butter. Beat until fluffy and light in color, about 1 minute. Beat in the vanilla and salt until combined.
Dry ingredients: Beat in heat-treated flour until just combined. Add milk one tablespoon at at time and beat until dough starts to come together. Stir in the miniature chocolate chips with rubber spatula.
Serve and store: Enjoy right away or store in an airtight container in the fridge for up to 1 week. It freezes well for up to 3 months. Thaw in the fridge overnight. Allow it to sit out at room temperature before serving again to soften slightly.
