Preheat your oven to 350 degrees F. Line just the bottom of a 10 inch tube pan. (See Best Tips #1 Above).
Place your sesame flour, baking powder, whey protein powder, sweetener and salt into a food processor. Pulse several times to combine (and aerate). Set aside.
Whisk the egg whites and water in a large metal mixing bowl until the mixture just starts to foam. Add the cream of tartar and begin whipping with the mixer on medium speed for 1 minute. Add the lemon extract and vanilla stevia and keep whipping on medium speed. Whip until medium peaks which should take between 3-5 minutes. Add enough of the dry mixture to just dust the top of the foam. Fold it in using a rubber or silicone spatula and repeat until almost all of the dry mixture is incorporated.
Gently spoon the batter into the ungreased tube pan and bake for 35 minutes. Use a long skewer or chop stick inserted half way between the outer wall and the center. If if comes out clean and dry, it's done, if not bake another 5 minutes.
Flip the pan over on its "feet" and allow to cool for 2-3 hours.
See storage instructions above the recipe.