Preheat your oven to 200 C/ 400 F and line a baking sheet with parchment paper. Cut 2 slices lengthwise from the center of the cauliflower head. Each piece should be around 1 inch (2.5 cm) thick and weigh about 100g.
To prepare the batter, add the almond flour, psyllium husk, onion powder, garlic powder, and salt to a bowl. Whisk to combine. Add the almond milk and mix until a thick batter forms.
Working with one cauliflower piece at a time, dip it into the batter. Cover both sides generously with the batter, then transfer to the baking sheet. Repeat with the second piece of cauliflower.
Bake for 25-30 minutes, flipping halfway through. They should be golden and crispy on the outside and soft in the middle. While the cauliflower burgers are cooking, prepare the hot sauce.
To a small bowl, add the hot sauce. Melt the vegan butter and drizzle it over the hot sauce. Whisk to combine.
Dip each cauliflower burger in the sauce and return it to the baking sheet. Bake for another 10 minutes until crispy. Set aside to cool for a couple of minutes.
Optionally serve the buffalo burgers inside Keto bread buns with a lettuce leaf. Add 1 tbsp of vegan ranch dressing on top of the patty. Serve immediately.