I made my usual Epicurious Christmas pudding recipe which I have made umpteen times before. This year when I steamed it in the oven as usual (in pudding bowl in pan of hot water) at 375 for 6 hours, I noticed that after about three hours the top began to burn (i.e. went v dark almost black) so I turned the heat down to 325 and took the pudding out after about 5 1/2 hours. For the first time in about 8 years, the top of the pudding didn't cohere and lumps came off. I assume this was because it was under cooked? If so, how can I stop the top getting overcooked in future? Any experts out there? Thanks.