In a large baking dish, whisk the plant-based milk, vegan protein powder, flax seeds, maple syrup, cinnamon, vanilla extract and salt. Set aside for 10 minutes.
Dip each slice of bread in the French toast mixture for 1 minute. Flip and wait another 30 seconds to 1 minute. The sturdier the bread, the longer you should soak it.
Heat a large pan or skillet with a little vegan butter or coconut oil. When hot, transfer the slices to the pan. Cook for 1-2 minutes on each side over medium heat.
Serve with fresh fruit, yogurt, icing sugar or maple syrup.