Ah I was wondering if I could just freeze it straight off - didn't know if it needed blanching at all. That's great news, I can pop the bulk in the freezer and just use a bit now.
Rhubarb and custard cake sounds deeeeeeelish! I saw someone else had mentioned a rhubarb and orange cake but I've not got around to looking it up yet. Also intrigued by rhubarb and cornmeal cake - never made a cornmeal or polenta cake so quite fancy giving that a try.
In fact I suppose I might have enough to do all of them!