1 large egg plus 1 large egg yolk, at room temperature
2 teaspoons pure vanilla extract
2 cups semisweet chocolate chips
1. Position the oven racks in the top third and center of the oven and preheat to 325°. Line two large rimmed baking sheets with parchment paper or silicone baking mats.
2. In a medium bowl, whisk the flour with the baking soda and salt. In a large bowl, beat the butter with the brown sugar, granulated sugar and corn syrup using an electric mixer on high speed until combined, about 1 minute. Beat in the egg, egg yolk and vanilla. With the mixer on low speed, mix in the flour mixture, just until combined. Mix in the chocolate chips.
3. Using 2 tablespoons per cookie, drop mounds of dough about three inches apart onto the prepared baking sheets. The dough can be frozen on the baking sheets until hard, then transferred to a ziplock plastic bag and stored in the freezer for up to one month. Bake without thawing.
4. Bake, rotating the positions of the sheets from top to bottom and front to back halfway through baking, until the cookies are lightly browned on the edges, about 18 minutes. (If using frozen cookie dough, bake about 20 minutes.) Transfer to a wire rack and cool completely. Repeat with remaining dough, using cool baking sheets.