Pre-heat the oven to 160ºC and spray baking sheets with a little low calorie cooking spray.
Place the butter and sweetener in a mixing bowl and beat together until light and fluffy. This will be quicker and easier if you use an electric hand whisk.
Add the egg and beat for another minute.
Sift the flour, cinnamon and baking powder into the bowl, add a pinch of salt and mix thoroughly with a spoon.
Tip out onto a lightly floured surface and knead gently until it forms a smooth dough.
Roll out to 2mm thickness and cut into star shapes using a 6cm cutter.
Place the stars on the baking sheet, leaving an inch or so between them.
Roll the scraps together and continue cutting out until all the dough has been used. You should get 40 stars with a 6cm cutter.
Bake in the oven for 15 minutes until the biscuits are golden.
Leave on the tray for 5 minutes, before transferring to a cooling rack.