Wash the broccoli well under cold water. Cut it into small florets. Steam the broccoli for about five minutes until slightly tender. Drain well and let it cool.

Preheat your oven to 350°F (175°C). Lightly grease a baking dish with cooking spray or butter to prevent sticking during baking.

In a large bowl, combine cream of mushroom soup, mayonnaise, beaten eggs, chopped onion, salt, and pepper. Stir everything until the mixture becomes smooth and creamy.

Place the steamed broccoli into the bowl. Gently fold it into the creamy mixture. Make sure every piece is coated evenly for the best flavor.

Mix in the shredded cheddar cheese. Stir carefully so the cheese spreads throughout the casserole mixture and creates a rich, cheesy texture.

Pour the mixture into the prepared baking dish. Spread it evenly with a spoon so the casserole cooks evenly from edge to edge.

In a small bowl, mix the crushed crackers with melted butter. Stir until the crumbs are coated. This creates a crispy golden topping.

Sprinkle the buttery cracker mixture evenly over the casserole. Cover the entire surface for a delicious crunchy finish after baking.

Place the dish in the preheated oven. Bake for about 35 minutes. The top should become golden brown and the center should be hot.

Remove the casserole from the oven. Let it rest for five minutes before serving. This helps the casserole set properly and improves texture.