Melt butter in a large skillet over medium heat and add sliced yellow squash and chopped onion. Sauté for about 8-10 minutes until squash is tender and onions are translucent.

Remove skillet from heat and let vegetables cool slightly. In a large mixing bowl, combine sautéed squash and onions with sour cream, cheddar cheese, garlic powder, onion powder, salt, and pepper. Stir until well combined.

Preheat oven to 350°F (175°C). Lightly grease a casserole dish with butter or cooking spray and transfer the squash mixture into the dish, spreading evenly.

Sprinkle crushed butter crackers evenly over the squash mixture. For extra flavor, mix the crackers with melted butter before topping.

Bake for 25-30 minutes, until edges are bubbly and topping is golden brown. Aromas will fill the kitchen.

Allow casserole to cool for a few minutes before serving. This helps to set the dish for easier serving.

Serve warm as a dish or alongside grilled meats or salads. Enjoy the comforting flavors of the casserole.