In mixing bowl, cream sugar and butter. Add in the egg and egg yolk, vanilla extract, and lemon extract.
In another bowl, stir together the flour, baking soda, baking powder, salt, and lemon zest. In a food processor, pulse the lemonhead candies. Add into the dry ingredients. Whisk everything together and then add to the wet ingredients. Mix until JUST combined.
Cover the dough and chill in the fridge for 1 hour. Roll into balls and bake on a parchment lined baking sheet (do not skip the parchment paper/silpat liner or these cookies won't come off the pan!)
Preheat the oven to 350 degrees F. Bake for 10-12 minutes. Let cool on the pan for a few minutes.
Prepare the glaze: whisk together the freshly squeezed lemon juice and powdered sugar until smooth. Brush generously over cooled cookies and if desired top with additional lemon zest.