In a bowl, combine flour and sugars; cut in butter until crumbly. Press into an ungreased 13x9-in. baking dish. Bake at 350° for 15-20 minutes or until edges begin to brown. , In a small bowl, combine brown sugar, flour and cinnamon; cut in butter until crumbly. Stir in pecans; set aside., Place squash in a large saucepan and cover with water; bring to a boil. Reduce heat; cover and simmer for 15-20 minutes or until tender. Drain. Transfer to a blender or food processor; cover and process until smooth. , In a large bowl, combine the sugars, cornstarch and seasonings. Gradually beat in 4 cups squash, milk and eggs until smooth (save any remaining squash for another use). Pour over crust. Sprinkle with topping. , Bake at 350° for 55-65 minutes or until a knife inserted in the center comes out clean. Cool on a wire rack. Cover and refrigerate overnight. , Garnish with whipped cream and additional cinnamon if desired. ,