Preheat oven to 375°F (190°C). Grease a 9×13-inch baking dish.
Steam the cauliflower until tender, about 5-7 minutes. Drain well and pat dry with paper towels. (For microwave steaming: Place florets in a microwave-safe bowl with 2 tablespoons of water, cover tightly with plastic wrap, and microwave for 5-7 minutes.)
In a large bowl, mix the cream cheese, sour cream, 1 cup of Colby Jack cheese, half of the crumbled bacon, half of the green onions, minced garlic, salt, and pepper.
Add the steamed cauliflower to the bowl and gently fold to coat it with the cheese mixture.
Transfer the mixture to the prepared baking dish. Top with the remaining 1 cup of cheese, the remaining bacon, and sprinkle with paprika.
Bake for 20-25 minutes, or until the cheese is melted, bubbly, and the edges are lightly browned.
Let the casserole cool for 5 minutes, then sprinkle with the remaining green onions before serving. Enjoy!