While the loaf is cooling, whisk the egg, almond milk, and vanilla in a shallow dish until fully combined.
In a separate shallow bowl, mix together the almond flour, granular erythritol, and cinnamon.
One at a time, dip the baked egg loaf slices into the egg coating, then dredge them in the almond flour mixture, and place them on a plate.
Heat a large skillet over medium heat and melt one tablespoon of butter in the skillet.
Place 4 slices in the skillet and cook for about 2 minutes on each side or until they turn golden brown. Remove them slices from the skillet and arrange on a plate.
Place the remaining butter in the pan and repeat with the remaining slices.
Garnish the french toast with walnuts, sugar-free syrup, berries, or confectioner erythritol.