Pre-heat oven to 350F (175C) and line 2, 18×13 inch (46cm x 33cm) half sheet pans with parchment paper or silicone baking mats. Combine all of the dry ingredients in a large mixing bowl. Now use a hand mixer to stir in the butter, eggs, and vanilla. Finally, fold in the chocolate chips. Reserve a little for the tops of the cookies, if desired. Scoop 18-21 cookies onto the lined baking sheets, about 2-3 inches (5-7.5cm) apart. Flatten them out by pressing down on the top slightly with clean fingers. Press the remaining chocolate chips evenly into the tops of each cookie. Bake for 10-12 minutes. The edges and tops will begin to brown. Let cool on the cookie sheets for 30 minutes. These will stay soft and delicious for at least 4 days in an airtight container. See notes for freezing instructions.