Pour neutral frying oil into a deep, heavy-bottomed saucepan to a depth of 2 to 3 inches. Heat over medium-high until it reaches 350°F. To test without a thermometer, drop a small bit of batter in — if it sizzles immediately, the oil is ready.
In a large mixing bowl, whisk together the flour, baking powder, salt, black pepper, paprika, and garlic powder. Slowly pour in the hot water while whisking until the batter is smooth and thick — similar to pancake batter. It should coat the back of a spoon but drip off slowly. Adjust with more water or flour as needed.
Pat the cauliflower florets completely dry with paper towels. Add them to the batter and toss until every piece is fully coated with no dry patches.
Using tongs or a slotted spoon, carefully lower 5 to 7 florets at a time into the hot oil. Fry for 3 to 4 minutes, turning once or twice, until deep golden and firm on the outside. Remove with a slotted spoon and drain on a paper towel-lined plate. Repeat with remaining batches.
For extra crunch, run each batch through the oil a second time for 1 to 2 minutes. This drives out remaining moisture and creates a shatteringly crispy shell.
Heat olive oil in a large skillet over medium-high heat. Add the minced ginger and cook for 1 minute until fragrant. Add the soy sauce, honey, sesame seeds, and flour. Whisk until the flour fully dissolves.
Pour in the water and add the apple cider vinegar. Stir to combine. Bring to a boil, stirring often, until the sauce is glossy, bubbling steadily, and slightly thickened.
Add all the fried cauliflower to the skillet at once. Gently fold and toss until every floret is evenly coated in the sauce. Serve immediately for maximum crunch.