Cut the cauliflower into evenly sized florets so they cook at the same rate.
In a large mixing bowl, whisk together the flour, milk, garlic powder, and salt until a smooth batter forms.
Add the cauliflower florets to the batter and toss until every piece is evenly coated.
Sprinkle the breadcrumbs over the battered cauliflower and gently mix until each floret is well coated.
Preheat the air fryer to 370°F (188°C) for a few minutes.
Arrange half of the cauliflower florets in the air fryer basket in a single layer to prevent overcrowding.
Air fry for about 10–13 minutes until the coating becomes golden and crispy.
Remove the cooked batch and repeat with the remaining cauliflower.
While the cauliflower cooks, heat vegetable oil in a small saucepan over medium heat.
Add the minced garlic and sauté briefly until fragrant and lightly golden.
Stir in the grated ginger and cook for about one minute to release its aroma.
Add soy sauce, honey, sesame oil, rice vinegar, chili paste, and water, whisking until smooth.
In a small bowl, mix cornstarch with water to create a slurry and add it to the sauce.
Bring the sauce to a gentle simmer and cook until it thickens into a glossy glaze.
Transfer the crispy cauliflower into a large bowl and pour the sauce over it.
Toss gently until all pieces are evenly coated.
Sprinkle sesame seeds and chopped green onions on top before serving.