01 - Preheat oven to 350°F and line two baking sheets with parchment paper
02 - Whisk together gluten-free flour blend, baking powder, and salt in a medium bowl until thoroughly combined
03 - Beat softened butter and granulated sugar in a large bowl until light and fluffy, approximately 2-3 minutes
04 - Mix in egg, vanilla extract, and lemon zest until fully incorporated into the butter mixture
05 - Gradually add dry ingredients to wet mixture, stirring just until a soft dough forms
06 - Drop tablespoon-sized dough balls onto prepared baking sheets, spacing 2 inches apart. Flatten each ball gently with palm or glass bottom
07 - Bake for 10-12 minutes until edges begin to turn golden. Remove promptly to prevent overbaking
08 - Let cookies rest on baking sheets for 5 minutes, then transfer to wire rack to cool completely
09 - Whisk powdered sugar, lemon juice, and lemon zest together until smooth and pourable
10 - Drizzle or spread lemon glaze over cooled cookies. Allow glaze to set before serving