Leave the butter out to come up to room temperature.
Mix all dry ingredients (flour, sugar, baking powder).
Add the butter, yolk and lemon zest to the dry ingredient mixture and make a dough using your hands.
Divide in 3, wrap each piece in cling film and leave in the fridge.
Once cooled, work with each piece at a time.
Line the tray with baking paper. Preheat the oven to 180 C.
Flour the surface and roll out the dough approx 3 mm thick.
Cut out the shapes with a cutter and transfer them to the tray.
Bake for 5 – 8 minutes or until the edges are just starting to get colour.
Wait for the shapes to cool down and sandwiched two pieces together with a jam.
Sprinkle with icing sugar.
Tip: Work quickly and cut the little round openings in the middle once the shapes are on the tray.