Preheat your oven to 450°F (232°C). Line a baking sheet with parchment paper or lightly grease it with cooking spray.
In a mixing bowl, combine the flour, garlic powder, onion powder, paprika, salt, black pepper, and cayenne pepper. Whisk until well mixed.
Gradually add the water (or plant-based milk) to the flour mixture, whisking continuously until you achieve a smooth batter.
Dip each cauliflower floret into the batter, ensuring it is fully coated. Allow any excess batter to drip off before placing it on the prepared baking sheet.
Once all the florets are coated, lightly spray or drizzle them with olive oil to help them crisp up during baking.
Bake in the preheated oven for 25 minutes, flipping the florets halfway through, until they are golden brown and crispy.
Remove from the oven and allow to cool slightly. Garnish with fresh parsley if desired, and serve hot.