01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - Whisk together gluten-free flour, baking soda, baking powder, and salt in a medium bowl.
03 - Cream butter and sugar in a large bowl until light and fluffy. Beat in egg, vanilla extract, lime zest, and lime juice until well combined.
04 - Gradually add dry ingredients to the wet mixture, mixing until just combined. Fold in shredded coconut.
05 - Scoop 1-tablespoon portions of dough and roll into balls. Roll each ball in extra granulated sugar, then place on prepared baking sheets 2 inches apart.
06 - Gently flatten each dough ball with your palm.
07 - Bake for 10-12 minutes, or until edges are lightly golden.
08 - Allow cookies to cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.