In a mixing bowl, combine milk and vinegar and let set for a few minutes to activate. Then add the rest of the wet ingredients: melted coconut oil, maple syrup, vanilla extract and whisk.
In another bowl, whisk together the dry ingredients: flours, starch, cocoa powder, salt, baking powder and sugar.
Pour the wet ingredients into the dry ingredients. Stir with a big spoon until just combined (the batter will still be a little lumpy). Let the batter rest for 10 minutes so the flour has time to soak up some of the moisture. Plug in your waffle iron to preheat now.
Once 10 minutes is up, give the batter one more swirl with your spoon. Pour batter onto the heated waffle iron, enough to cover the center and most of the central surface area, and close the lid. Once the waffle is crisp, transfer it to a cooling rack or baking sheet. Don't stack your waffles on top of each other, or they'll lose crispness. If desired, keep your waffles warm by placing them in a 200 degree oven until you're ready to serve.
Repeat with remaining batter. Serve waffles with ...