01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together the gluten-free flour, shredded coconut, sugar, baking soda, and salt until evenly distributed.
03 - In a large bowl, beat the softened butter until creamy. Add the egg, lemon zest, lemon juice, and vanilla extract, then beat until smooth and well incorporated.
04 - Gradually add the dry ingredient mixture to the wet ingredients, mixing until just combined. Avoid overmixing.
05 - Scoop tablespoon-sized portions of dough and roll into balls. Place them 2 inches apart on the prepared baking sheets. Gently flatten each ball with your palm or the bottom of a glass.
06 - Bake for 10 to 12 minutes, or until the edges are lightly golden. Cool on the baking sheets for 5 minutes, then transfer to a wire rack to cool completely.
07 - In a small bowl, whisk together the powdered sugar with 1 tablespoon of lemon juice. Add more lemon juice as needed until you achieve a thick but pourable glaze consistency.
08 - Drizzle the glaze over the completely cooled cookies. Allow the drizzle to set before serving.