“Pumpkin”-Filled Tortelli with Butter and Sage

The pumpkin used in Italy for this delicious filled pasta is a rich and sweet squash called zucca barucca. In the States, I use sweet potato instead of pumpkin because the flavor of zucca barucca most closely approximates the orange-fleshed sweet potatoes (sometimes called yams), more than the pumpkin available here. The shape is identical to the tortelloni in the previous recipes, but they are a specialty of Mantova and Ferrara, where they are called tortelli. Some mak