Pre-heat oven to 180C / 350F
In a big mixing bowl, combine almond milk and apple cider vinegar and let sit for 10 minutes. It should curdle slightly.
Add vanilla extract, maple syrup and oil. Whisk to combine.
Process quick oats in a food processor or high-speed blender until the texture resembles a fine powdery flour.
Add salt and baking powder, and blitz to combine.
Add dry flour mixture to mixing bowl, and gently fold it into the liquid mixture until combined. Do not over-mix.
Fill donut pan with batter (about 2/3 full).
Bake for 10 minutes or until an inserted stick comes out clean.