- 1 cup unsalted butter , melted and cooled at least 10 minutes (226g)
- 1 ¼ cup brown sugar tightly packed (250g)
- 1/2 cup sugar (100g)
- 1 large egg + 1 yolks (room temperature preferred)*
- 1 ½ teaspoon vanilla extract
- 2 ¾ cups all-purpose flour (350g)
- 2 teaspoons cornstarch
- 1 teaspoon baking soda
- 3/4 teaspoon salt
- 1 3/4 cup semisweet chocolate chips (plus additional for tops, optional) (300g + additional)
- Combine melted butter and sugars in a large bowl. Stir very well.
- Add egg and egg yolk, stir well.
- Stir in vanilla extract. Set aside.
- In a medium-sized bowl, whisk together flour, cornstarch, baking soda, and salt.
- Gradually add flour mixture to wet ingredients — stir well so that all the flour is absorbed.
- Stir in chocolate chips.
- Place dough in refrigerator and chill for 30 minutes.
- Preheat oven to 350F (177C) and prepare cookie sheets by lining with parchment paper.
- Scoop dough by rounded 1 Tablespoon (or 30 grams) onto prepared cookie sheets, placing at least 2″ apart.
- Bake on 350F (177C) for 10 minutes — cookies may still seem slightly soft in the centers, that is OK, they will cook completely on the cookie sheets. Don’t over-bake or your cookies will be too hard.
- If desired, gently press additional chocolate chips into the tops of the warm cookies.
- Allow to cool completely on cookie sheets.