Preheat your oven to 400 degreed F

Now place your squash and onion into a large skillet, and put it over a medium heat. Be sure to pour in a small amount of water. Cover this, and cook it until the squash is tender. It will take about 5 minutes. Drain well afterwards, and place it into a larger bowl.

Now in a medium sized bowl, mix together your cracker crumbs and your cheese. Stir in half of this mixture into the cooked squash and onions. In a smaller bowl, mix together your milk and eggs before adding to the squash mixture. Now stir in 1/4 cup of melted butter, and season it with salt and pepper. Spread this into a 9 x 13 inch baking dish. Before putting this in the oven, sprinkle the remaining cracker mixture on top and dot with 2 tablespoons of butter.

Bake the casserole into the preheated oven for about 25 minutes, or until it is lightly browned.