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.
¼ teaspoon Salt, 2 ¼ Cup Gluten Free 1-to-1 Flour Blend
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.