Preheat oven to 350. Prepare a 2 litre casserole dish with cooking spray; set aside. Cook mostaccioli pasta according to package directions except omit the salt. Drain. In a skillet, cook turkey, bell peppers, and onions until no pink remains in turkey and vegetables are tender. Stir in salt, oregano, cinnamon, 0.125 teaspoon nutmeg, tomato sauce, and garlic. Alternate layers of mostaccioli and meat mixture in prepared dish. Heat margarine in a saucepan over low heat until melted. Stir in flour and remaining nutmeg. Cook over low heat, stirring constantly, until smooth and bubbly; remove from heat. Boil and stir 1 minute. Spoon sauce over mostaccioli and meat mixture. Sprinkle with cheese. Bake uncovered for 35 minutes.