Preheat the oven to 180°C
Combine the sugar, cinnamon and margarin in a bowl.
Unroll the pastry sheet, cut off about quarter lengthwise and set aside.
Spread the cinnamon sugar over the remaining pastry, then fold the pastry in half.
Roll it out with a rolling pin.
Using a sharp knife or pizza cutter, cut strips of pastry lengthwise, approximately 2cm wide.
Pick up a pastry strip and fold back and forth on itself, leaving it wider at the bottom (about 5 cm) and narrower at the top (about 1cm),to look like a Christmas tree.
Push a wooden skewer through the middle of each folded pastry layer, then spread the layers out evenly on the skewer.
Repeat with the other strips. You should get about 9 trees. Put them on a baking tray, lined with parchment paper.
Using a cookie cutter, stamp out small stars from the remaining pastry.Put these on the baking tray too.
Bake for 12-15 minutes, until the pastry is puffed up and golden.
Let them cool, then push the stars on top of the tree skewers.
Sprinkle with icing sugar just before serving.