Grease a 15 cm round cake tin. Sift the flour and baking powder together into a mixing bowl. Add the margarine and rub it in. Stir in the sugar. Dissolve the instant coffee in the milk. Add the milk to the bowl and mix to a soft dough. Put the dough on a lightly floured surface and knead it gently until smooth. Roll out to an oblong about 25 x 20 cm.
Making the Filling
Melt 15 g of the margarine and brush it over the dough to within 25 mm of the edges. Mix the castor sugar with the cinnamon and instant coffee and sprinkle the mixture onto the dough. Sprinkle on the sultanas. Moisten the edges of the dough with a little water and roll it up like a swiss roll. Cut into 6 pieces with a sharp knife. Place the slices, cut side up in the cake tin and bake in a very hot oven 220 C for 20 minutes or until cooked. Melt the remaining margarine and brush it over the hot scone.