1 butternut squash (about 2 pounds), peeled, halved lengthwise, seeded, and cut into 1/2-inch dice
2 tablespoons olive oil
1 teaspoon salt
1/8 teaspoon fresh-ground black pepper
1 1/4 teaspoons dried sage
1 cup mascarpone cheese
1/2 cup half-and-half
3 scallions including green tops, chopped
3/4 pound penne
1/4 pound sliced smoked ham, such as Black Forest, cut into thin strips
1/4 cup grated Parmesan