I have a recipe for Polish Honey Cake that comes to me by way of the British Isles. The recipe calls for one small tin (150 g) of sterilized cream. What the? I'm told that condensed milk is not a substitute, but I have no idea what is. The recipe calls for 8 oz. of butter as well, so I'm thinking that heavy cream wouldn't be a proper substitute either. Anyone know what this "sterilized cream" is?