Preheat oven to 350°F and line baking sheets with parchment paper.
In a large bowl, cream together butter and ½ cup powdered sugar until light and fluffy, about 3 minutes.
Mix in lemon zest and 2 tablespoons lemon juice until well combined.
Add flour and salt, mixing on low speed until dough comes together. Don't overmix!
Roll dough into 1-inch balls and place 2 inches apart on prepared baking sheets. Flatten slightly with the bottom of a glass.
Bake for 10-12 minutes until edges are just beginning to turn golden. Cool on baking sheet for 5 minutes, then transfer to wire rack.
While cookies cool, whisk together 1½ cups powdered sugar and 3 tablespoons lemon juice until smooth.
Drizzle glaze over cooled cookies and let set for 30 minutes before serving or packaging.