Step 1: Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper.
Step 2: In a large bowl, cream together the softened unsalted butter and 3/4 cup powdered sugar with an electric mixer until light and fluffy (about 2-3 minutes).
Step 3: Beat in the lemon zest, fresh lemon juice, and vanilla extract until well combined.
Step 4: In a separate medium bowl, whisk together the all-purpose flour and salt. Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined and a soft dough forms. Be careful not to overmix.
Step 5: Roll the dough into 1-inch balls and place them about 1 inch apart on the prepared baking sheets.
Step 6: Bake for 12-15 minutes, or until the edges are just set and very lightly golden (the cookies should still be pale). Do not overbake.
Step 7: Remove from the oven and let cool on the baking sheets for 5 minutes before carefully transferring them to a wire rack to cool completely.
Step 8: Once completely cooled, dust generously with additional powdered sugar before serving.