Preheat oven to 425ºF. Line 2 large baking sheets with parchment paper. In a small bowl, combine flour, garlic powder, oregano, salt, paprika and pepper. In a separate large bowl, beat egg. Add cauliflower florets to egg bowl and toss to coat. Sprinkle flour mixture onto cauliflower; toss to coat.
Divide cauliflower between baking sheets; spreading evenly. Lightly coat with cooking spray. Roast for 20 minutes, stirring once or twice.
Meanwhile, in a small saucepan, combine hot sauce and ghee; warm on low heat, whisking, until ghee is melted. When cauliflower is done, divide sauce between baking sheets, drizzling on cauliflower, taking care not to let breading fall off.
Switch oven to broil on high. Broil 1 to 2 minutes per sheet, until spots not covered with sauce are golden. Sprinkle with parsley (if using).