Preheat your waffle iron according to the manufacturer’s instructions.
In a small bowl, combine non-dairy milk and apple cider vinegar. Let sit for 5 minutes to curdle slightly.
In a large mixing bowl, whisk together flour, sugar, baking powder, baking soda, and salt.
Pour in the milk-vinegar mixture, oil, and vanilla extract. Whisk until smooth—do not overmix.
Lightly grease the waffle iron if needed. Pour enough batter to cover the waffle grid without overflowing.
Cook until golden and crisp, about 4–6 minutes per waffle (time may vary depending on your waffle iron).
Transfer to a cooling rack if you want them extra crispy, or serve immediately with toppings like fruit, syrup, or nut butter.