Preheat oven to 350°F
Wash and slice squash into small medallions or dice into smaller pieces of the squash is large. I prefer smaller sized squash since it is tender. Put squash into a large bowl for mixing with the filling.
In a separate bowl, mix together the soup, mayo, eggs, cheese, onions, salt, and pepper. Pour over squash. Stir until well mixed. Then pour into a casserole dish for baking.
Crush crackers in a resealable plastic bag. Melt butter in the microwave and stir into crackers until moist.
Drizzle on top of casserole.
Bake at 350°F until bubbly and brown on top (usually 45-50 minutes). Bake for 30 minutes covered with foil to help prevent crackers from burning. Then uncover and bake an additional 20 minutes until golden brown on top.