01 - Preheat the oven to 350°F. Line two baking sheets with parchment paper.
02 - In a large bowl, whisk together almond flour, gluten-free flour, baking powder, and salt until well blended.
03 - In a separate bowl, rub the lemon zest into the granulated sugar with your fingertips to release the citrus oils.
04 - Add eggs, lemon juice, vanilla extract, and melted butter to the sugar mixture. Whisk until smooth and thoroughly combined.
05 - Pour the wet ingredients into the dry ingredients. Stir until a thick, cohesive dough forms.
06 - Refrigerate the dough for 15 minutes to firm up, making it easier to handle and shape.
07 - Scoop tablespoon-sized portions of dough and roll them into smooth balls between your palms.
08 - Roll each dough ball first in granulated sugar, then generously coat in powdered sugar until completely covered.
09 - Place the coated dough balls 2 inches apart on the prepared baking sheets to allow for spreading.
10 - Bake for 11 to 13 minutes until cookies are puffed, crackled on top, and just set while remaining soft in the center.
11 - Let cookies rest on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.