Mix together the margarine, 50g sugar and cinnamon to make a paste and set aside.
Sift the flour into a bowl.
Stir in the other 50g sugar, yeast, cinnamon and salt.
Pour in the milk and melted margarine and bring together to form a smooth and elastic dough.
Cover and leave in a warm place to double in size.
Knock back and form into a smooth ball. Roll out to a rectangle approximately 30cmx10cm
Spread the cinnamon paste over the dough, leaving a gap around the edge and roll up to form a long sausage shape. Place into a greased bundt tin or small cake tin, cover and leave to rise again. An hour in a warm place should be adequate
Place in a preheated oven and bake at 180 degrees centigrade fan/190 degrees centigrade non-fan/gas mark 5 for 20-25 minutes, until golden and cooked through (it will sound hollow when tapped on the bottom.)
Remove from the tin and cool. Dust liberally with icing sugar before serving
Cool