Cook first 3 ingredients in boiling water to cover, in a Dutch oven for 25 minutes or until squash is very tender. Drain well and mash mixture with a fork
Crush 10 crackers and stir into squash mixture. Stir in 1/2 cup cheese and the next 5 ingredients.
Spoon mixture into a lightly greased 11″ x 17″ baking dish.
Crush remaining 6 crackers and sprinkle over casserole. Sprinkle remaining 1 cup shredded cheese evenly over casserole.