Adjust your oven rack so it’s in the middle position and preheat to 425°.
Lightly oil a 9-inch round baking pan.
Clabber the soy milk by combining it with the apple cider vinegar in a small bowl. Allow the mixture to sit for 5 to 10 minutes.
Combine the flours, baking soda, and salt in a large bowl, and whisk to combine.
Add the clabbered soy milk to the dry ingredients, and mix with a wooden spoon or rubber spatula until just combined. The mixture will be sticky.
Fold ¼ cup of sunflower seeds and 2 tablespoons of flax seeds.
Scrape the mixture into the prepared baking pan. Brush the top with the aquafaba and sprinkle on the remaining sunflower seeds, flax seeds, and the rolled oats. Use a large serrated knife to cut a large “x” into the dough, about 1” deep. You may need to wipe the knife with a damp cloth between cuts.
Bake for approximately 35-45 minutes, until the bread has risen and is golden brown.
Place the pan on a cooling rack for 10 minutes. Carefully remove the bread from the pan, and place on the cooling rack and allow to completely cool.