Toss the cauliflower with ~2 tbsp of olive oil then add it to a baking sheet. Roast the cauliflower on a baking sheet for 25 minutes. The cauliflower will get tender and some parts will brown up.
While the cauliflower is roasting, make the cheese sauce: Add butter, the white parts of the green onions, and the garlic cloves to a skillet on medium heat. Sauté until the onions are translucent (~3 minutes)
Add heavy cream, cream cheese, salt, ranch seasoning (if you’re using it), and pepper to the skillet with the onions, garlic and butter. Turn the heat to medium low and continue to cook until the cream cheese is melted. Stir in 1.5 cups of the cheddar cheese to finish the cheese sauce.
Mix the cheese sauce and the roasted cauliflower, then add it to a baking dish. Top it with the remaining cheddar cheese and roast for an additional 20 minutes, or until the cauliflower is tender.
Top the baked cauliflower, with some dollops of sour cream, the green parts of the green onions, and the crumbled bacon.
Notes
Roast the cauliflower on a baking sheet for 20-25 minutes or make air fryer roasted cauliflower. The cauliflower will get tender and some parts will brown up.