In a large mixing bowl, use a wooden spoon to mix the sugar, flour, and butter.
Add in the vanilla and tea and mix until well incorporated.
Shape the dough into a log and wrap it in wax paper. Keep in the fridge for 2 hours or overnight.
Once the dough has set, slice cookies from the log and place them onto a baking sheet.
Bake for about 24 minutes or until the cookies are golden brown. The thickness of your cookies will alter the baking time. Be sure to turn the pan halfway through baking.
Lemon Icing
Mix the ingredients in a mixing bowl until an icing forms.
Drizzle onto the cooled shortbread cookies and let dry.