12 egg whites, room temperature
½ cup of cake flour, sifted
½ cup of unflavored or vanilla protein powder
¾ cup of stevia or no-calorie sugar substitute
½ tsp. of salt
1 ½ tsp. of cream of tartar
1 tsp. of vanilla extract
2 large lemon, zested and squeezed
Preheat the oven to 325F.
In a medium bowl, combine flour, salt, and protein powder. Sift together three times. Set aside.
On high-speed setting, beat egg whites and cream tartar in a large, clean bowl by using an electric mixer for one minute or until medium peaks are formed.
Lower to a medium-speed setting and sprinkle stevia over the egg whites mixture. Continue whisking for 2 minutes.
Turn off the electric mixer. Add vanilla extract, lemon juice and lemon zests.
Continue to whisk the egg whites mixture on a high-speed setting for a minute.
Add ¼ batch of shifted salt, flour, and protein powder mixture (dry mixture) into the whipped egg mixture. Fold in the mixture gently with a spatula. Continue adding a ¼ batch of dry mixture at a time and gently folding until all ingredients are incorporated.
Pour the batter into an ungreased 10-inch tube pan (angel cake pan) or a lightly greased and floured Bundt pan. Distribute evenly and gently tap the pan on the counter, couple times, to remove air pockets.
Bake for 35-40 minutes or until the cake is dry to the touch and the surface is golden brown.
Cool upside down on an elevated cooling rack/wire for an hour before removing from pan. Loosen the sides of the cake with a knife if necessary.