In a small bowl, make the flax eggs by combining the ground flaxseed and water. Stir and set aside for 10 minutes to thicken. In a liquid measuring cup, add the almond milk and apple cider vinegar. Stir and set aside for 10 minutes to curdle (vegan buttermilk).
Preheat the oven to 200 degrees F. Place a wire rack on a baking sheet. This is so you can keep the waffles warm while cooking the others. Preheat waffle iron.
In a large bowl, add the flour, sugar, baking powder, baking soda, and salt. Whisk until well combined.
In a medium bowl, add the melted butter, sourdough discard, flax eggs, almond milk mixture, and vanilla. Whisk until well combined.
Add the wet to the dry. Whisk until combined, your batter will be thick. Once waffle iron is hot, spray with oil or grease and cook waffle batter according to waffle iron’s instructions or until golden brown and crisp. Remove and set on the wire rack. Place the baking sheet with the wire rack and finished waffles in the oven to keep warm and crisp while you cook the rest of the batter.
Serve warm with fruit, nut butter, maple syrup, or whatever toppings you like! Enjoy!