Preheat the oven to 375 degrees.
Spray an 8 x 8 baking dish with cooking spray and set aside.
Steam the cauliflower for 8 minutes or place in a bowl of water in the microwave for 8 minutes or until tender.
In a large bowl combine the cauliflower, sour cream, half the cheese, half the bacon, salt, pepper, and garlic powder. Mix until combined.
Pour the cauliflower into the prepared dish.
Sprinkle the top of the casserole with the remaining cheese and bacon.
Bake for 15-20 minutes or until the cauliflower is heated through.