Ingredients
Equipment
Method
Prep and preheat
- Preheat the oven to 350°F and grease a 9x13-inch baking dish for easy release. Set it aside while you cook the squash.
Cook the squash mixture
- Cook the sliced yellow squash and diced onion in 2 tbsp butter for 10-12 minutes until tender, stirring occasionally. Drain well in a colander so the casserole doesn’t turn watery.
- In a mixing bowl, combine the shredded sharp cheddar, sour cream, mayonnaise, beaten eggs, salt, and black pepper until evenly mixed. Fold in the drained squash and onion until coated.
- Spread the squash-cheese mixture into the greased baking dish, smoothing the top. Press lightly to level so the topping bakes evenly.
Add topping and bake
- Toss the crushed Ritz crackers with the melted 3 tbsp butter until the crumbs look evenly coated. Sprinkle the buttery crumbs over the casserole for a golden crust.
- Bake at 350°F for 30-35 minutes until the top is golden and the center looks set. Let it rest briefly before serving so the slices hold their shape.
Notes
For the best texture, drain the cooked squash well—excess moisture is what can make the bake loose. Store covered in the refrigerator up to 4 days; reheat individual portions in a 325°F oven until warmed through. Freezing is not recommended because the squash can soften further. If you want a lighter option, use light mayonnaise and reduced-fat cheddar for a similar flavor with fewer calories.
