01 - Preheat the oven to 350°F. Line two baking sheets with parchment paper and set aside.
02 - In a medium bowl, whisk together the gluten-free flour blend, almond flour, baking soda, and sea salt until evenly distributed.
03 - In a large bowl, beat the softened butter and granulated sugar together using an electric mixer until pale, light, and fluffy.
04 - Add the egg, lemon zest, fresh lemon juice, and vanilla extract to the butter mixture. Beat until smooth and well combined.
05 - Gradually add the dry ingredient mixture to the wet ingredients, mixing on low speed until just combined. Do not overmix.
06 - Gently fold the chopped pistachios and white chocolate chips into the dough using a spatula until evenly distributed.
07 - Scoop tablespoon-sized mounds of dough onto the prepared baking sheets, spacing them approximately 2 inches apart to allow for spreading.
08 - Bake for 11 to 13 minutes, or until the cookie edges are lightly golden and the centers appear just set.
09 - Allow the cookies to rest on the baking sheets for 5 minutes, then transfer to a wire cooling rack to cool completely before serving or storing.