In a medium bowl, whisk together flour, baking powder, and salt. Set aside.
In a large bowl using an electric mixer, cream together butter, sugars, egg, and limoncello on medium speed; beat until smooth.
Add flour mixture to wet ingredients; mix on medium speed just until combined.
Scoop dough into 1.5 tablespoon balls, or use a #40 disher to scoop balls of dough. Place on an ungreased baking sheet or silicone mat/parchment paper lined baking sheet, 2 inches apart.
Bake for 9-11 minutes or until golden brown around the edges.
Cool cookies on cookie sheet for 3 minutes; transfer to wire rack and cool completely.
Glaze Icing
In a small saucepan, combine all the glaze icing ingredients except for the powdered sugar.
Heat the ingredients in the saucepan on low until the sugar is melted, then turn the heat to medium to bring to boil. Boil for 3 minutes, stirring continuously, then remove from heat and immediately pour into a heat-safe glass bowl.
Add powdered sugar and whisk until combined. Allow to cool and thicken, 10-15 minutes.
Using a knife or icing spatula, spread icing onto the cookies and then allow to cool completely. Icing will thicken as it cools. Eat & Enjoy!
Notes
Glazed Limoncello Cookies should be stored in an airtight container and will keep 4+ days.Recipe adapted from Life, Love and Sugar.