01 - Preheat oven to 350°F. Line two baking sheets with parchment paper and set aside.
02 - In a medium bowl, whisk together gluten-free flour blend, baking powder, and salt until evenly distributed.
03 - In a large bowl, beat softened butter and ¾ cup granulated sugar until light and fluffy, approximately 2 minutes.
04 - Beat in egg, vanilla extract, and rosewater until fully incorporated into the butter mixture.
05 - Gradually add dry ingredients to wet mixture, mixing until just combined. Do not overmix.
06 - Gently fold chopped pistachios into the dough until evenly distributed throughout.
07 - Scoop tablespoon-sized portions onto prepared baking sheets, spacing 2 inches apart to allow for spreading.
08 - Flatten each dough ball slightly with fingers or glass bottom. Sprinkle with extra sugar, chopped pistachios, and rose petals if desired.
09 - Bake for 10–12 minutes until edges are lightly golden. Centers may appear slightly underbaked.
10 - Let cookies rest on baking sheet for 5 minutes, then transfer to wire rack to cool completely before serving.