¾cup(170 g) unsalted butter, melted and slightly cooled
¾cup(150 g) packed light brown sugar
½cup(100 g) granulated sugar
1egg, room temperature
1egg yolk, room temperature
2teaspoonspure vanilla extract
1 ½cups(250 g) semisweet chocolate chips
Instructions
Preheat oven to 350 F. Line an 8x8 baking pan with parchment paper and set aside.
In a medium bowl, whisk together flour, cornstarch, baking soda and salt. Set aside.
In a separate large bowl, whisk butter, brown sugar and sugar until light in color, about 2 minutes. Add egg, egg yolk and vanilla. Mix until incorporated. Add flour mixture to wet ingredients and mix just until combined. Stir in chocolate chips by hand.
Transfer dough to prepared baking dish and press down evenly using a spatula or your hands. Bake for 25 to 30 minutes or until the edges are set and the center is soft. Allow bars to cool in the pan for 10 minutes before lifting out of the pan, slicing and serving.
Notes
Store chocolate chip cookie bars in an airtight container at room temperature for 3 or 4 days.Freeze dough for up to 3 months. Defrost in the refrigerator before bringing to room temperature and baking.Freeze baked bars in an airtight container for up to 1 month.