Cut the baby tomatoes in half and fry in very hot oil for about 6-7 minutes, they should get a bit mushy but not brown, add salt. You need to do this in a large deep frying pan.
Cook the spaghetti until really 'al dente' - if it says 8 minutes on the pack, take them out at 5.
Drain the pasta really well and pour into the tomatoes and boiling oil (if the oil is hot enough it will make a big noise). Add peperoncino and stir a little to get oil around all the spaghetti.
Leave for about 2-3 minutes before stirring/moving around/turning the burned parts around and then leave again for another 2-3 minutes. If you stir continuously the crusty brown bits don't get formed.