Put plenty of water on to boil for the pasta, waiting for it to come to the boil before salting it. Add the pasta and cook according to packet instructions, until al dente
While the pasta is cooking, make the sauce by putting all the remaining ingredients, except the basil, into a processor and blitzing until you have a coarse textured sauce.
Just before draining the pasta, remove a cupful of pasta-cooking water and add 2 tablespoonfuls of it down the funnel of the processor, pulsing as you go.
Tip the drained pasta into your warmed serving bowl. Pour and scrape the sauce on top, tossing to coat (add a little more pasta-cooking water if you need it) and scatter with basil leaves.