In medium bowl whisk together baking soda, baking powder, salt and flour.
In large bowl, cream together butter and sugar until light and fluffy.
Add egg, vanilla, lemon extract and lemon zest.
Add flour mixture, a cup at a time, and stop once combined.
Roll 2 Tbsp into a ball and place onto baking sheet, keeping them 2 inches apart.
Dip a glass into sugar and press each ball lightly, just until flattened.
Bake for 13 minutes or just until barely browned on the bottom; allow to cool.
Make lemon glaze: Mix all of the icing ingredients together in a Pyrex measuring cup with a whisk until smooth and no lumps; let it sit for a few minutes then pour/spoon it on each cookie.