Preheat your oven to 425°F (220°C) and line a baking sheet with parchment paper. Trust me, don't skip the parchment paper unless you enjoy scraping sticky bits off your pan later.
Whisk together the flour, water, salt, black pepper, and garlic powder in a bowl until smooth. The batter should coat the back of a spoon nicely.
Dip each cauliflower floret into the batter, making sure it's fully coated but not drowning. Place them on your prepared baking sheet with space between each piece (they need room to get crispy!).
Bake for 20-25 minutes, flipping halfway through. You're looking for golden brown and crispy on the outside.
While the cauliflower works its magic in the oven, make your sauce. Heat a small saucepan over medium heat and add soy sauce, maple syrup, rice vinegar, sesame oil, ginger, and garlic. Stir well and bring to a gentle simmer.
Add the cornstarch-water mixture to the simmering sauce, stirring constantly. The sauce will thicken in about 2 minutes. Once it coats the back of your spoon, remove from heat.
When the cauliflower is perfectly crispy, toss it in the sticky sesame sauce until every piece is beautifully coated.
Sprinkle with sesame seeds and serve immediately while it's still hot and crispy. I like to serve this over rice or quinoa, but it's honestly good enough to eat straight from the pan.