Bokie Pokie

unsalted butter, softened (1 stick) • + 2 Tbsp all-purpose flour (167g) • granulated sugar • brown sugar, packed • vanilla extract • large egg yolk, room temperature • lemon zest (2-3 lemons) • baking soda • baking powder • salt • sugar, coating (optional)

salted or unsalted butter • packed light brown sugar • granulated sugar • large egg + 1 egg yolk • vanilla extract • all purpose flour • cornstarch • baking soda • salt • semi-sweet chocolate, chopped • milk chocolate chips