Baked Ziti with refried

2 tablespoons extra virgin olive oil 4 ounces thinly sliced pancetta , chopped 2 lbs pork shoulder, cut into 1 and 1/4-inch cubes 1 lb hot sausage , casings[...]

1 lb dried ziti pasta kosher salt 3 1/2 cups quick tomato sauce 1 lb fresh mozzarella cheese , half cut into 1/2-inch cubes and half thinly sliced 3/4 cup[...]