Homemade Squash Casserole

I'm posting the full recipe for this but I halved it when I made it because I had a sneaky feeling that my people were not going to be as on board with this as I was. I LOVED it, I mean I love squash casserole so no surprise. Everyone else, not so much. But they don't love casseroles like this so...their opinions just don't count. This recipe was adapted from Chef in Training.

3 cups water
1 cup chopped onion
3 cups chicken broth
10 cups sliced yellow squash
1 1/2 cups shredded cheddar cheese
1/2 cup sour cream
1/4 cup mayonnaise
4oz cream cheese (softened)
1 1/2 tsp salt
1/2 tsp pepper
1/2 tsp garlic powder
1 egg
1 1/2 cups crushed ritz crackers
4 tbsp butter

Heat oven to 350. Grease a 9x13 pan.  In a large pot bring the water, chopped onion and chicken broth to a boil. Add the squash and bring to boil with the squash. Reduce heat and simmer for 6-8 minutes. Remove from heat and drain the squash and onions. In a large bowl combine the sour cream, mayonnaise, cream cheese, salt, pepper, garlic powder and egg. Stir well. Carefully stir in the squash. Stir in the cheddar cheese. Pour into the greased baking dish.  Top with the crushed ritz crackers. Cut the butter into small slices and place over the top of the crackers. Bake in the oven for 25 minutes. Remove from oven and let sit for 10 minutes before serving.