01 - In a large bowl, beat the softened butter and powdered sugar until light and fluffy, approximately 2-3 minutes.
02 - Blend in the lemon juice, lemon zest, and vanilla extract until fully incorporated.
03 - Add the salt, flour, and cornstarch, mixing until a soft, cohesive dough forms.
04 - Divide dough in half and roll each portion into 1-inch diameter logs. Wrap in plastic and refrigerate for at least 30 minutes.
05 - Preheat oven to 350°F and line two baking sheets with parchment paper.
06 - Unwrap chilled dough and slice into 1/4-inch rounds. Arrange on prepared sheets, spacing 1 inch apart.
07 - Bake for 10-12 minutes until edges are barely golden.
08 - Let cookies cool on sheets for 5 minutes, then gently toss in powdered sugar while still warm.
09 - Transfer to wire rack and cool completely. Dust with additional powdered sugar before serving.