Mix the cauliflower with the melted butter, smoked paprika, salt, and pepper and toss together. Bake the cauliflower for 15 minutes.
In a large bowl mix the heavy cream, sour cream, 1 cup of the cheddar, half the bacon, half the green onions, and salt and pepper well. Pour in the roasted cauliflower and toss together.
Pour the mix into the casserole dish, sprinkle the rest of the cheddar, bacon, and green onions on top, and bake for 20-30 minutes.