In a small bowl, whisk together the eggs, milk, salt, & pepper. In another bowl, mix together the crumbled cheese crackers with the butter & then add the shredded cheese. Stir half of the crumb mixture into the squash along with the egg mixture. Combine well. Pour into a 2 to 3 quart casserole dish, and top with the remaining cracker/cheese mixture. Bake for 30 minutes.