01 -
Preheat oven to 400°F. In a large mixing bowl, add the cold cubed butter, sugar, and brown sugar. Cream together for 4 minutes or until light and fluffy, scraping the sides of the bowl halfway through mixing.
02 -
Add the egg, egg yolk, lemon zest, fresh lemon juice, and lemon extract (if using). Mix until well combined. For more intense lemon flavor, you can add additional lemon zest.
03 -
Gently fold in the flour, cornstarch, baking soda, and salt just until combined - don't overmix. Fold in the lemon flavored chips or white chocolate chips until evenly distributed throughout the dough.
04 -
Divide the dough and roll into large 6-ounce balls (it's helpful to use a food scale for consistent sizing). Place on a light-colored baking sheet, leaving plenty of space between cookies. Bake for 9-11 minutes until the edges are just set but the centers remain soft.
05 -
After removing from the oven, allow the cookies to set on the baking sheet for at least 10 minutes before transferring to a cooling rack.