With a lemon zester, shave the rind of the lemon until you have enough zest. Set aside.
Cut the lemon in half and squeeze out the juice into a small bowl (or use a juicer to make it easier!)
In a medium bowl, add powdered sugar, lemon juice, and 1 tablespoon of milk. Mix with a whisk or a fork. Continue adding milk ½ tablespoon at a time and mix between each addition. You will probably use about 3 tablespoons of milk total, but the consistency should be thin, similar to maple syrup.
Add the zest and give the glaze one last stir.
Drizzle over cakes or cookies using a spoon or a piping bag.
Let the glaze harden over baked goods at room temperature for 30 minutes.
Notes
Storage: Lemon glaze can be stored in an airtight container in the refrigerator for up to 5 days.