Preheat the oven to 350˚F / 175˚C. In a big bowl, mix together the dry ingredients: flour, almond flour, baking powder, baking soda, and salt.
In another large bowl, use a hand mixer to blend the wet ingredients: melted butter, agave, sugar, lemon extract, vanilla extract, lemon zest, and lemon juice.
Gradually combine the dry ingredients into the wet ones until well mixed.
Use a cookie scooper to place dough on a parchment-lined baking sheet. Flatten each cookie to about 1/4 inch thick using a glass or measuring cup. Freeze the cookies for 15 minutes before baking.
Bake for 9-10 minutes. The cookies will still look pale but will continue to cook as they cool. Allow them to cool completely before adding the glaze.
While the cookies cool, whisk together all the lemon glaze ingredients until smooth.
Frost each cookie with glaze and sprinkle with lemon zest.