Position the oven racks in the top and bottom thirds of the oven and preheat to 375 degrees. Line 2 large cookie sheets with parchment paper.

In a large bowl, whisk together the flour, baking soda, cream of tartar, and salt.

Add the butter and both sugars to another large bowl and cream together on medium speed for 1 minute, until the mixture is light but still a bit grainy.

Add the corn syrup, egg and egg whites, and vanilla and beat on medium speed until combined. The mixture should be a little runny.

With the mixer off, add all of the flour, then beat on low speed just until incorporated. Use a wooden spoon to stir in the chocolate chunks.

Working in batches, use a tablespoon or cookie scoop to drop the cookies onto the parchment lined cookie sheets about 3 inches apart.

Bake for 6 minutes, then rotate the sheets top to bottom and back to front. Continue baking 6 more minutes, or until the cookies are a little brown around the edges.

Cool on the cookie sheets for 5 minutes, then gently transfer to wire racks until cooled completely.