What chocolate on a cappuccino?

At home, I sometimes like to make a cappuccino (I don’t order it in coffee shops, usually far too much froth) But I’m stumped as to what to sprinkle on it. Previously I’ve used the stuff that comes with the instant cappuccino sachets, but I’m not buying them just for that.

It’s not cocoa (too bitter). Not hot chocolate (dissolves). Other than shaving actual chocolate, what do I use? And why don’t they sell it in the coffee aisle? I’ve found some online, in 1kg bags (or worse, TEN 1kg bags!) but that’s a bit much… Can I make it from cocoa and… something?

I know we have a few baristas on the board, so maybe you can tell me?

What kind of chocolate do you top a capp with?

(in the UK, btw, but I’ve searched a few US supermarkets too. Either would do!)