Add about an inch of water to a large pot. Set a steamer basket in the pot and bring water to a boil. Add broccoli and place lid on pot. Steam until crisp tender, about 5 minutes. Cool.
Cook bacon in a nonstick skillet. Remove and set aside.Discard all but 2 tablespoons of bacon grease. Cook the onion and mushrooms in the bacon grease until the mushrooms are golden. Cool.
In a large bowl, whisk together cream of chicken soup, mayonnaise, sour cream, eggs, garlic powder, salt and pepper.
Stir broccoli, onions and mushrooms into soup mixture.Crumble the bacon and add half of it and 1 cup of shredded cheddar cheese to the bowl and mix in.
Transfer mixture to a greased 2½ to 3-quart baking dish. Sprinkle remaining cheese and bacon on top.
Sprinkle crushed crackers on top and drizzle with butter.
Bake for 30 to 40 minutes. Cover with aluminum foil if getting too brown before the baking time is up.
Notes
To make spicy, add 1/2 teaspoon of crushed red pepper flakes.Frozen broccoli can be used instead of fresh. Thaw completely before using and blot with paper towels to get rid of excess moisture.Nutritional info is provided as an estimate only and will vary based on brands of products used.