Combine lemon zest and sugar in a small bowl. Use your fingers to rub the zest into the sugar to impart the lemon oils.
2 teaspoon Lemon Zest, ¾ Cup Sugar
Combine lemon sugar and butter in the bowl of an electric mixer. Beat on medium speed for 3 minutes until light in color and fluffy. Scrape down the bowl.
¾ Cup Vegan Butter
Add the egg, vanilla and limoncello and beat another 60 seconds until combined. Scrape down the bowl.
1 Egg, ½ teaspoon Vanilla, 2 Tablespoon Limoncello Liqueur
Turn the mixer to the lowest speed. Add the flour and salt. Mix until all of the dry ingredients are incorporated.
Cover the mixing bowl with plastic wrap and refrigerate for 4 hours up to overnight.
Preheat oven to 350F degrees. Line two baking sheets with parchment paper.
Remove chilled dough from the refrigerator and scoop into balls about the size of a golf ball. Place onto prepared baking sheet. Flatten using your hand or a cookie stamp. The cookies will not spread much so you can space them about an inch apart.
Bake in preheated oven for 10-12 minutes until cookies are setup but not browned on top.
Remove from oven and cool for 10 minutes on the cookie sheet, then transfer to a wire rack to cool completely.
For the lemon glaze
Sift powdered sugar into a small bowl.
2 Cup Powdered Sugar
Add the limoncello and lemon zest to the sugar. Mix together until smooth.
Working one at a time, dip the cookies into the glaze and then place them on a wire rack to dry. Once the glaze has dried, the cookies can be stored in an airtight container.
Notes
Storage: Store cookies in an airtight container at room temperature for 3-4 days.Freezing: Package into a freezer container with as much as removed as possible. Freeze up to 2 months. Bring to room temperature before serving.