Step 1

In a large bowl, whisk together flour, baking soda, salt, and sugars until well blended. Stir in chocolate chips. Store in an airtight container.

Step 2

Adjust oven rack to center position. Preheat oven to 325°F. Line cookie sheets with parchment paper (or spray with nonstick cooking spray).

Step 3

Fluff/stir cookie mix to aerate and redistribute the chocolate chips. Measure 4 scant cups of Chocolate Chip Cookie Mix into a bowl, using a knife to level each cup. By hand or with an electric mixer, blend in cooled melted butter, whole egg, egg yolk, and vanilla. Mix until combined.

Step 4

Use a tablespoon or small cookie scoop to measure out cookie dough and roll it into a ball. Place ball on prepared cookie sheet and flatten slightly. Repeat, spacing cookies two inches apart.

Step 5

Bake for 9 to 11 minutes or until edges of cookies are starting to turn golden brown and centers are puffy yet set. Remove from oven and allow cookies to cool completely on cookie sheets.