Preheat your oven to 425°F (220°C).
Cut the cauliflower into bite-sized florets.
In a bowl, toss the florets with olive oil, garlic powder, salt, and pepper.
Spread the cauliflower evenly on a baking sheet.
Roast in the preheated oven for 25-30 minutes, or until golden brown.
Remove from the oven and toss with Buffalo sauce.
Layer the coated cauliflower on a serving platter and sprinkle cheese on top.
Return to the oven for an additional 5-7 minutes or until the cheese is bubbly.
Top with blue cheese crumbles and sliced green onions before serving.