Prepare the Squash: Start by slicing the squash into thin pieces. Heat a skillet over medium heat, and cook the squash with a bit of butter for about 5-7 minutes until it softens. Drain any excess water to prevent the casserole from becoming too watery.
Mix the Ingredients: In a large bowl, combine the cooked squash with cheddar cheese, Milk, melted butter, onion, and eggs—season with salt and pepper to taste. Stir everything together until well combined, making sure the cheese and eggs are evenly distributed.
Add the Ritz Crackers: Take one packet of Ritz crackers and crush them up. Fold the crushed crackers into the squash mixture, setting aside the other packet to sprinkle on top for a perfect, crispy topping.
Assemble and Bake: Transfer the mixture into a greased casserole dish. Sprinkle the remaining crushed crackers over the top. Bake in a preheated oven at 350°F (175°C) for 40-45 minutes, or until the casserole is golden brown and bubbly on top.
Serve and Enjoy: Let the casserole cool for a few minutes before serving. This rich, cheesy, and flavorful dish is perfect for any occasion, from family dinners to holiday meals.