1. Preheat the oven to 450 degrees.
2. In a large bowl, whisk together the buttermilk, flour, and garlic salt, whisking until mostly smooth (it’s ok if there are a few lumps left).
3. Very gently (cauliflower can be pretty delicate), place the cauliflower in the bowl and lightly toss to completely coat with the buttermilk mixture.
4. Place the cauliflower in a shallow baking dish and bake for about 15-18 minutes or so (watch it, it may start to brown up quickly on you.)
5. Meanwhile, combine the buffalo sauce and the melted butter in a small bowl.
6. Carefully remove the hot cauliflower from the oven and pour the buffalo sauce mixture over it, stirring gently to coat it as best you can.
7. Return the cauliflower to the oven and bake for another 5-8 minutes or so. Let cool slightly and serve immediately.