Add oats to a blender along with vegan buttermilk, flax egg, vegetable oil or melted vegan butter, sugar, and vanilla extract. Blend until smooth.
In a mixing bowl, whisk together all-purpose flour, salt, baking soda, and baking powder.
Pour the blended wet ingredients into the dry mix and whisk to combine. (The ingredients can also be mixed in the blender. I prefer to mix them in a bowl because the batter thickens as it sits, and it can become hard to get every last bit out of the blender at the end.)