HEAT 1 tablespoon oil in a large, nonstick skillet over medium heat. Add pumpkin. Cover; cook, stirring occasionally, for 15 minutes or until tender. Remove and keep warm.
HEAT remaining tablespoon oil and butter in skillet. Add mushrooms, shallot and garlic. Cook, stirring frequently, for 8 to 10 minutes or until mushrooms are tender. Return pumpkin to skillet; stir in half-and-half, oregano, salt and pepper. Cook for 1 minute or until heated through.
WHILE sauce is cooking, prepare pasta according to package directions. Drain, reserving a little pasta water. Add pasta to sauce in skillet and toss, adding a little pasta water if needed.
SERVE sprinkled with pumpkin seeds.
