Whisk the flour, cornstarch, baking soda, cinnamon, and salt together in a large mixing bowl.

In a separate large mixing bowl, use an electric mixer to beat together the butter, sugar and brown sugar. Beat the mixture until the ingredients are completely combined and creamy.

Stir the milk and vinegar together in a small cup, then add them to the butter mixture along with the vanilla. Beat the mixture again until combined.

Begin adding the flour mixture to the butter mixture, adding about a cup at a time and beating it in before the next addition.

Fold in the chocolate chips.

Cover the bowl with plastic wrap and place it in the fridge. Chill the dough for 30 to 60 minutes, until it has firmed up a bit but isn't rock solid.

Preheat the oven to 375°F and line a couple of baking sheets with parchment paper.

Use a cookie scoop or spoon to drop rounded 2 tablespoonfuls* of the dough onto the baking sheets, leaving about 2 inches between them.

Place the baking sheets into the oven and bake the cookies until the dough has spread out and the edges are just barely beginning to brown, 9 to 10 minutes**.

Transfer the baking sheets to cooling racks and allow the cookies to cool until set before removing them from the baking sheets.