Heat oven to 350 degrees. Spray baking dish with non-stick spray.
Cut cauliflower in to medium to small chunks. Steam until tender.
Using a potato ricer, "rice" cauliflower into a medium bowl.
Add sour cream to "riced" cauliflower and stir. Save some of the green onion, bacon and cheddar cheese for garnish. Add remaining green onions, bacon and cheddar cheese and stir.
Add salt and pepper to taste.
Place mixture into prepared baking dish. Bake for approximately 20 minutes or until bubbly and heated through.