Put the ham and mozzarella in a saucepan. Add the cream and Parmigiano-Reggiano. Turn on the heat to low and cook for just a few minutes until the cream is slightly reduced. Drop the rigatoni into the boiling salted water and cook until "al dente" (firm to the bite); drain immediately.
Transfer to a butter smeared baking dish, add the sauce and toss thoroughly. Place in an oven preheated to 400 F and bake for 15 minutes. Allow to settle for a few minutes before serving.