In a large bowl, combine the ingredients for the buttermilk marinade.
Transfer the cauliflower florets to the marinade and let sit for 20 minutes, stir to cover all pieces.
While the cauliflower is marinating begin combining all ingredients for the flour mixture in a separate large bowl. In addition, combine the buffalo sauce and melted vegan butter in a separate small bowl to make the buffalo sauce mixture. Set aside.
Begin heating the oil in a large frying pan over medium heat.
Once the cauliflower is done marinating, transfer the florets to a separate medium sized bowl, reserving the leftover liquid.
In the same bowl that now has the leftover marinade liquid, add in 1 cup of unsweetened almond milk and ¾ cups of all-purpose flour. Whisk to combine (will not be totally smooth, but mostly).
By now, your oil should be hot enough to begin frying. To test, flick a tiny bit of water in the pan. If it sizzles and pops, it's ready. If not, wait a few more minutes before beginning. It's important that the oil is hot enough before beginning to fry.
Arrange your three bowls in the following order: cauliflower florets (furthest from the stove), liquid batter, flour mixture (closest to the stove).
Use a spoon, tongs or your hands to dip the cauliflower pieces into the liquid batter, then into the flour mixture, back into the liquid batter, and into the flour mixture again, then into the hot oil in the frying pan.
Repeat this process for each piece of cauliflower, for as many as you can comfortably fit in the pan at once without over-crowding. Rotate the pieces as necessary, browning on each side. Once the fried pieces feel hardened after touching with tongs, it's okay to flip.
Transfer the fried cauliflower from the pan to a plate lined with paper towels to absorb the excess oil.
Let cool for about 5 minutes. Only drizzle or toss the ones you are going to eat with the Buffalo Sauce mixture to taste and garnish with chopped green onion. Enjoy!