I'd leave them for now to let them regrow if possible.

Yep. Just prune off anything that doesn't sprout.

So sorry to hear of this mindless destruction. Hope the raspberry canes and anything else not completely burned recovers. On the positive side, burning is often used as a measure to clear out various bug infestations and much of the undergrowth (in this case - roots and un-germinated seeds) often recovers to grow better and bug-free. I hope that's the case for you. :o)