Preheat oven to 350°F.

In a large skillet, melt 3 tablespoons of butter over medium heat.

Sauté the sliced squash and diced onion until they are soft and lightly golden, about 10–12 minutes. Let cool slightly.

In a large mixing bowl, combine sour cream, cream of chicken soup, beaten eggs, shredded cheddar cheese, garlic powder, paprika, salt, and pepper.

Stir in the sautéed squash and onion mixture until everything is well blended.

Spoon the mixture into a greased 9x13-inch baking dish.

In a small bowl, mix the crushed Ritz crackers with the melted butter.

Sprinkle the cracker mixture over the top of the casserole.

Bake for 30–35 minutes or until golden brown and bubbly.

Let sit for 5 minutes before serving.