Preheat oven to 400˚F.
Lightly grease a baking sheet with cooking spray and set aside.
Add egg whites to a large ziploc bag; add cauliflower florets to the bag, close it, and shake it around until everything is well combined.
In a separate ziploc bag combine the panko crumbs, paprika, cumin, garlic powder, salt, and pepper; add the cauliflower florets to the bag, close it, and shake it around until everything is well combined and coated.
Transfer the cauliflower florets to the prepared baking sheet; bake for 15 to 18 minutes, or until tender and lightly browned.
In the meantime, prepare the sauce in a nonstick skillet set over medium heat; combine the sesame oil, honey, soy sauce, vinegar, chili sauce, and garlic and bring to a simmer.
Simmer for 10 minutes.
In a small mixing bowl combine cornstarch and water and stir until the cornstarch is dissolved.
Whisk the cornstarch mixture into the soy sauce mixture and whisk to combine; remove from heat.
Remove the cauliflower florets from the oven and either add them to the sauce OR pour the sauce over the florets. Mix and toss until well combined.
Garnish with toasted sesame seeds and green onions.