Preheat the oven to 160°C, fan 140°C, gas 3 and line 2 baking sheets with baking parchment.
Put the flour, sugar, baking powder and cinnamon in a large mixing bowl. Add the butter and eggs. Mix together until it comes together as a smooth dough. Halve the dough, wrap 1 piece in cling film and chill.
Dust a work surface with flour, roll out the dough to about 5mm thick and cut out biscuits using different sized star cutters. Re-roll the leftovers and cut out more until all the dough is used up. Do the same with the remaining chilled dough. Arrange the biscuits on the trays and bake for 20 mins until lightly golden. Transfer to a wire rack to cool. Decorate with your choice of decorations.