1 c == 1 metric cup == 250 milliliters but its not too critical.
I'm still making this for my everyday breakfast. I use frozen or fresh berries when I have them (about 1 cup). I tried grated pumpkin and some pie type spices and it was OK. Currently It's late winter here and I'm using up the no-sugar plum and chia seed jam I froze last summer (~ 1/3 cup). The first rhubarb leaves are just up so it will be back to rhubarb soon, then blueberries as they're just starting to flower as well.