Heat the water and sugar together in a saucepan over medium heat until the sugar has dissolved. Stir in the butter, followed by the biscuit crumbs, coconut and rum. Mix well using a wooden spoon until combined and then remove from heat.

Take one torte layer from the package and place on a serving tray. Spread half of the filling on this layer. Top with another torte layer, pressing down lightly all over the layer. Now spread the remaining filling over this layer and top with a third torte layer, once again pressing down lightly.

To make the glaze: combine the butter or margarine with the chocolate a double boiler. Allow to melt and then stir well to make a smooth paste. Pour over the torte, and then place torte in the refrigerator to allow glaze to set.

Cut into squares before serving.