Preheat the oven to 180°C/160°C tan /gas 4. Line a baking tin with baking parchment. In a mixing bowl, combine all the batter ingredients and whisk until the mixture is smooth and slightly thick.
In a separate bowl, combine the breadcrumb mix. Add the cauliflower pieces and leaves to the batter and mix to coat evenly. Next, place the cauliflower in the breadcrumb mix and coat evenly. Place the cauliflower on the lined baking tin and bake for 18-20 minutes, flipping halfway through, until the cauliflower is golden brown and crispy.
Meanwhile, make the buffalo sauce. In a pan over medium-low heat, stir together the hot sauce, ketchup, butter, oat milk and maple syrup as it comes to a simmer, then cook for 2-3 minutes.
In a small bowl, whisk together the cornflour and water until well combined. Reduce the heat under the pan and stir in the cornflour mixture for about 2 minutes, until smooth and silky. Remove from the heat and set aside.
Put the baked cauliflower in a large mixing bowl, add a few spoonfuls of the buffalo sauce and mix to coat evenly.
Serve hot, with a sprinkle of sesame seeds, spring onions and chives.