Preheat oven and prep cauliflower – Preheat oven to 450°F (230°C). Line a large baking sheet with parchment paper and spray generously with oil. Chop cauliflower into bite-sized florets and set aside.
Batter the cauliflower – In a large bowl, whisk soy milk and apple cider vinegar. Let sit for 1 minute. Add flour, cornstarch, garlic powder, onion powder, and salt. Whisk until smooth. Add cauliflower and toss until fully coated.
Add breadcrumbs to coat – Sprinkle breadcrumbs into the bowl and mix until cauliflower pieces are evenly coated.
Bake – Spread cauliflower onto prepared baking sheet. Spray lightly with oil and bake for 20–25 minutes, flipping halfway, until crispy and golden.
Make the bang bang sauce – While baking, whisk vegan mayo, sweet chili sauce, sriracha, and agave until smooth.
Toss with sauce – Transfer crispy cauliflower to a bowl and toss with sauce. Optional: return to oven for 5 minutes to help sauce caramelize slightly.
Serve – Enjoy immediately as finger food or serve in tacos with red cabbage, diced tomatoes, and cilantro. This Easy Bang Bang Cauliflower is best hot and crispy.