1. Prepare the Crust:

1. Preheat oven to 350°F (175°C). Line baking sheets with parchment paper.
2. In a large bowl, cream together butter and powdered sugar until light and fluffy. Mix in lemon zest, lemon juice, and vanilla extract.
3. In a separate bowl, whisk together flour, cornstarch, and salt. Gradually add to butter mixture, mixing until just combined.
4. Roll dough into 1-inch balls and place 2 inches apart on prepared baking sheets. Bake for 10-12 minutes until bottoms are lightly golden.
5. Cool cookies on baking sheet for 5 minutes, then transfer to wire rack. Dust generously with powdered sugar while still warm.