Wash and dry the cauliflower then break into 1" pieces (use a knife if necessary for larger pieces), set aside
In a bowl, combine the ¼ Cup all-purpose flour,¾ Cup Cornstarch, 1 tsp baking powder, ½ tsp Salt
Add the water and egg and stir until smooth
Heat oil to 375℉
Working in batches, dip the cauliflower pieces into the batter, then shake off any excess batter and drop the pieces into the hot oil slowly.
Cook until golden brown and crispy (about 3 minutes) then remove to a paper towel lined rack to drain, salt or season immediately. Continue in batches until all of the cauliflower is done.
While the cauliflower cooks, make the bang bang sauce
Combine the ½ cup Mayonnaise, 3 Tbsp Sriracha or other hot sauce of choice, 1 Tbsp sweet Thai Chili Sauce, and 1 tsp rice wine vinegar (or other vinegar)