If you want to make a novelty cake but don�t have the right shaped tin, make an inner lining for a cake tin with a double thickness of heavy-duty foil and shape it accordingly. Teddy-bear birthday cakes, a romantic Valentine heart-shaped cake or a decorative Christmas-tree cake are all easy to make. Just place the lining in a large tin before filling it with the cake mixture� the lining should be as tall as the tin.