Pre-heat the oven to 200°C, 400° F, Gas Mark 6.
Place the cranberries, caster sugar, port and Ground Cinnamon in a small saucepan. Cook on a medium-heat for 10-15 minutes, stirring occasionally until the cranberries have popped.
Roll out the pastry and use a medium round pastry cutter to cut out 12 discs. Use the trimmings to cut out the same quantity of star shapes.
Use the discs to line a non-stick patty tin and spoon in 1 tsp of the sauce, brush the under side of the stars with water and place on top of the tartlet.
Bake for around 15 minutes or until the pastry is golden brown. Dust with icing sugar to serve.