Verdict: Yes! We have n̶o̶ bananas!

Well, I've tried one of the cupcakes now. The flavours aren't as coherent as they were in my head, so it's a slightly strange mish-mash of tastes. But it's pretty decent overall - I'm not convinced by the chocolate chips though; I don't really know if they go that well with the rest of the cake. But the sweetened mascarpone works wonderfully and the texture is absolutely wonderful. It's mostly a good recipe I think, but needs a bit of tweaking - perhaps just going down the plain banana bread cupcake route is the way forward.