In a small mixing bowl, combine flaxseed, milk, and apple cider vinegar. Set aside.
In a large mixing bowl, combine flour, sweetener, baking powder, baking soda, and salt. Add in flaxseed mixture and use whisk to combine until no flour clumps remain. Add in small amounts more of non-dairy milk as needed to achieve pourable consistency without becoming thin.
Fry pancakes in frying pan on stovetop over low to medium heat using cooking spray as needed to prevent sticking. After preheating pans, pour 1/2 cup servings into a circle. Allow to cook until bubbles begin to form and edges just begin to dry, then flip and cook briefly on the other side until golden.