Whisk the oat milk and apple cider vinegar in a small bowl and let sit for 5 minutes to curdle.
In a large mixing bowl, whisk together the flour, sugar, baking powder, and salt.
Add the vegetable oil and vanilla extract to the oat milk mixture and whisk to combine.
Pour the wet ingredients into the dry ingredients and whisk until just combined, ensuring some small lumps remain for fluffiness.
Preheat a non-stick griddle or skillet over medium heat and lightly grease with oil.
Scoop 0.25 cup of batter per pancake onto the griddle.
Cook until bubbles form on the surface and edges appear dry, approximately 2 to 3 minutes.
Flip and cook the other side until golden brown, approximately 1 to 2 minutes.