Set oven to 410F.
Chop the florets off the head of the cauliflower.
Spread the florets on a baking sheet and spray them with olive oil.
Season with garlic powder, onion, cumin, smoked paprika and pepper and rub the season into the florets to ensure they are all coated.
Roast for 15 minutes then remove them from the oven and place them in a large bowl.
In a separate bowl, mix together arrowroot starch and BBQ sauce.
Pour the sauce over the florets, and shake the bowl to mix.
Place the florets back on the baking sheet and roast for another 5 to 10 minutes.