Preheat oven to 350° F. Prepare pan (10 x 15 with sides works best) with oiled parchment paper or a silicone mat.

Mix dry ingredients with a whisk.

Add wet ingredients to the dry mixture. Stir completely. Make sure there aren't any obvious strings of egg white left in the batter.

Let batter sit 2 - 3 minutes to thicken up. If left too long, it will be difficult to spread.

Pour batter onto pan. It will likely mound in the middle, so you'll get a more even thickness if you spread it away from the center somewhat, in a rectangular shape. The closer you get to the edge of the pan you get, the thinner your bread will be, so stop an inch or two from the edge.

Bake for about 20 minutes, or until it springs back when you touch the top and/or is visibly browning even more than the flax already is.

Cool and slice into desired size and shape.