Whisk together the flour, baking powder, baking soda, and salt, then set aside. Cream together the butter and sugar. Add egg, lemon zest, lemon juice, and vanilla extract, then mix.
1
Add the flour mixture to the butter mixture in three parts and combine. Place the cookie dough on prepared baking sheets.
2
Bake and let cool. Meanwhile, make the lemon icing. Then, ice the cooled cookies and let them set.
3