Prep: Combine the flax and water in a small bowl and mix well. Add the apple cider vinegar to the soy milk and swirl to curdle and form vegan “buttermilk”; let both mixtures sit for at least 5 minutes.
Dry Ingredients: In the meantime, whisk the oat flour, brown rice flour, baking powder, salt, and cinnamon together in a large bowl. Form a well in the center of the bowl.
Wet Ingredients: In a separate bowl combine the flax, milk, maple syrup, and vanilla together. Add this to the center of the dry ingredients, then mix well. The batter should look slightly runny, but will thicken in a few minutes. If your batter is too thick, add additional milk in 1 tablespoon increments.
Cinnamon Swirl: In a small bowl mix the almond butter, maple syrup, cinnamon, and salt until a thick paste forms. Scoop this into a piping bag (or ziploc with the corner cut) and set aside.
Bake: Warm a large pan or skillet over medium heat and grease with cooking spray or oil/butter of your choice. Pour about 1/3 cup (80 ml) of the batter onto the skillet to form each pancake. Once the edges have set, carefully pipe a cinnamon “swirl” over each pancake. Cook for 2 to 3 minutes total on this side, then flip the pancake and cook for an additional 2 to 3 minutes. Carefully remove the pancake from the pan (so as not to damage the swirl), and transfer to a cooling rack or baking tray, swirl side up. Repeat with the remaining batter; this recipe should make around 12 pancakes in total.
Serve: Serve the pancakes warm, topped with maple syrup or icing sugar. Store any leftovers in the fridge for up to 5 days, or in the freezer for up to 1 month.