Crust

1. Preheat oven to 350 degrees.
2. In a medium bowl, cut cold butter into baking mix and powdered sugar.
3. Press into 8 x 8 square baking dish.
4. Bake for 10 minutes or until golden brown.

Filling

1. In the same bowl, beat together the granulated sugar, baking mix, eggs, limoncello and lemon zest.
2. Pour over crust and bake for 25 minutes.
3. Remove from oven and run a knife around the edges to loosen.

Glaze

1. In a small bowl, whisk the powdered sugar and limoncello until smooth.
2. Spread evenly on top of the squares and let set.
3. Cut into 64 squares.
4. Freeze or refrigerate in an airtight container.
5. Enjoy!