Here is my clubs list of local cafe stops, with contact details. Some of them are out of the area you are looking at, but there are plenty to choose from. I'd highly recommend Dedham, just because it is a beautiful place, and getting to and from it involves some of the best cycling country in the SE of England, in my view. This is the Dedham cafe, from that list:
Dedham, Art Centre Tea Rooms......01206 322677
You can't miss it. If you don't have a good reason to go into Colchester, then I would avoid it, personally, because it is a bit busy, and not that cycle friendly.
Mike