Cut apart the head of cauliflower and rinse it with water.
In a medium bowl or large resealable bag, combine olive oil, salt, pepper and garlic powder.
Add cauliflower and toss to coat evenly.
Cover a baking sheet with aluminum foil and lightly grease it with cooking spray. Arrange the cauliflower on the baking sheet in a single layer.
Bake at 400 degrees for 1 hour. Turn the cauliflower every 20 minutes so the edges brown evenly. The browner the edges, the crispier and tastier the cauliflower poppers. Enjoy the baked cauliflower poppers with a side of ketchup!