Preheat the oven to 350°F. Put the pumpkin in a roasting pan, drizzle with the oil, cover with foil and bake for about 1 hour. Pass the pumpkin through a food mill into a bowl, add the Parmesan and eggs and season with salt and pepper. Stir in enough bread crumbs to make a fairly firm mixture. Roll out the pasta dough into a sheet and stamp out 3-inch rounds with a cookie cutter. Spoon a little of the pumpkin filling into the center of each round, fold in half and crimp the edges. Cook the tortelli in a large pan of salted, boiling water for 10 minutes. Meanwhile, melt the butter in a skillet, add the sage and cook for a few minutes. Drain the tortelli, place in a warm serving dish and sprinkle with the sage butter and extra Parmesan.