Preheat your oven to 450 degrees. You will need a large baking sheet. Even if you use a non-stick pan you should still lightly spray with cooking oil.
In a medium size bowl combine flour, garlic powder and water. Whisk until completely mixed together.
Place you florets in the flour mixture and coat thoroughly. Once coated place on baking sheet and cook for 20 minutes.
In a small bowl combine the melted butter and Sriracha sauce together.
At the 20 minutes mark pour the hot sauce mixture over the cauliflower. I used a basting brush and brushed the hot sauce on. I did this so that I could make some that would be less spicy for my daughter. Cook for an additional 5 minutes.