Add almond milk, flaxseed, cinnamon and stir. If your batter appears extremely gloppy, add more almond milk to thin it out. It should be pourable. (Vanilla is optional.)
Let batter rest for 5 minutes while you preheat your griddle or skillet to medium heat.
Once your surface is hot, coat generously with vegan butter or coconut oil (I used Earth Balance because I like the flavor).
Dip your slices of bread into the batter and let it rest for 5-10 seconds on each side, using your fingers to make sure it's fully submerged. Transfer immediately to griddle. An optional step is to sprinkle the freshly-dipped sides with a little almond meal for added texture.
Cook for 3-4 minutes on each side or until evenly golden brown. Flip carefully using a sturdy spatula as the banana mixture can be a bit sticky if you're not gentle. If your french toast appears to be browning too quickly or burning, turn down your griddle.
Serve immediately with desired toppings. I think peanut butter and maple syrup are all you need here.