Place sweet potato and squash in a large Dutch oven, and cover with water; bring to a boil. Reduce heat, and simmer, uncovered, 20 minutes or until tender. Drain well; set aside.
Sautée pear (I used apple juice) until tender.
Preheat oven to 350° F.
Place squash mixture, pear, sugar, and next 5 ingredients in a food processor; process until smooth. Spoon mixture into a 11 x 7 (I needed a 9 x 13) baking dish coated with cooking spray.
Place low-fat granola and brown sugar in a small heavy-duty zip-top plastic bag. Seal bag, and crush mixture with a rolling pin. sprinkle granola mixture over casserole. Bake, uncovered, at 350° F. for 30 minutes, or until topping is golden.
Servings: 12 1/2 cup