Preheat oven to 425˚F(220˚C). Prep a greased baking sheet.
In a large bowl, add flour, cornstarch, and spices and whisk together. Then add in 1 cup non-dairy milk and apple cider vinegar and stir together with a spatula just until combined. If needed to have a pourable consistency, add another tablespoon of milk until desired consistency.
In a food processor, add the cornflakes and spices. Pulse until combined and into small but still shaped pieces. You don't want dust here. Pour into a separate large bowl. Set up the cauliflower next to the bowl of wet mixture, then the bowl of dry beside that.
Dip a cauliflower floret into the wet mixture, letting any excess drip off. Then, add to the dry mixture ensuring that all sides are coated. Place onto prepared baking sheet. Baked for 18-20 minutes or until golden brown.
For the Waffles
Add non-dairy milk and apple cider vinegar into a large bowl and allow to sit for 10 minutes to form a vegan buttermilk. Once time is up, add butter (if adding), sugar, vanilla and salt and whisk together. Sift in flour and baking powder and use a spatula to bring together, not overmixing.
Make waffles according to your waffle maker with the batter. Repeat until no mixture remains.
When finished, top a waffle with some of the cauliflower. Add green onions if desired. Drizzle with syrup and/or hot sauce.