Preheat the oil to 350 degrees Fahrenheit. Line a baking sheet with parchment paper and top with a cooling rack. Set aside.
Cut the cauliflower: Remove the green leaves from the bottom and trim the stump. Turn the cauliflower right-side-up and cut into quarters. From each quarter, trim the center by making a cut diagonally. Using hands, break cauliflower into florets.
In a large mixing bowl, combine flour, salt and set aside. For wet batter, add buttermilk, coriander, cayenne pepper, paprika, garlic, onion powder, allspice and mustard powder and salt.
Add cauliflower florets to dry batter, wet and then dry, mixing bowls and using tongs, coat evenly. Place cauliflower on the prepared baking sheet and allow the excess batter to drip from the cooling rack to the parchment paper.
Deep fry for 5-7 minutes until golden brown. Place on cooling rack to drain out oil.
When cauliflower is done cooling down, pour on buffalo sauce to coat each piece.
Serve with ranch, carrots, and celery.