This double cooking means that it is served soft, not with the firm al dente consistency that some Italians prefer in pasta dishes.
Southern Italy has a tradition of wood-burning ovens and open-flame grills.
A wood-fired oven and al forno dishes are a feature of many Italian restaurants.
Brick and clay ovens are a key feature of cuisines of the Mediterranean and Middle East, with wood being the main fuel for many parts of Europe for many centuries.
[1] The dictionary definition of al forno at Wiktionary