The 7L Halogen Pot is not suitable for baking a cake weighing 1 lb or above, even if the Extension Ring is used. The diameter of Glass Container is too short, which limits the size of cake. Heat will not be able to go through the centre if the cake is too tall. We suggest using the Casserole Pot (optional accessory) to bake the cake with the 7L Halogen Pot in order to ensure a better circulation of heat, but the cake will still be less than 1 lb.