In a small bowl whisk together the butter, hot sauce, vinegar, Worcestershire and garlic until completely combined.
Set aside until ready to use. If not using right away, store the sauce in an airtight container for up to a week – whisking to combine before using.
For the cauliflower:
Fill a large pot with enough oil to reach 2" (5cm) up the side of the pan. Heat oil to 350°F (180ºC).
In a large bowl whisk together the cornstarch, flour, baking powder, garlic powder, salt and pepper.
Slowly add ¾ cup cold water, whisking until a thin batter forms (about the consistency of pancake batter). If needed, add more water 1 tablespoon at a time until the desired consistency is reached.
Working in batches, dip the cauliflower in the batter, letting the excess batter drip off. Add to the hot oil and deep-fry until the cauliflower is golden brown, about 4 minutes.
For serving:
Remove to a large bowl and toss with ¼ cup of the buffalo sauce. Serve immediately with carrots, celery and ranch or blue cheese dressing.