Preheat oven to 350F and lightly grease two 6-inch round cake pans or one 8-inch round cake pan with butter or olive oil.
In a medium-size bowl, combine the beaten eggs, maple syrup, olive oil, vanilla extract and lemon zest.
In a large mixing bowl, add the almond flour, carob powder, baking powder, cinnamon, and kosher salt. Mix thoroughly.
Then add the wet mixture into the dry mixture. Mix well until well-incorporated and no large lumps remain.
Once fully combined, fold in the whipped egg whites using the cut and fold technique. The batter should be thick but pourable.
Divide batter evenly between prepared cake pans and bake on a center rack for 35-40 minutes. Or until a toothpick inserted in the middle comes out clean and the edges and surface appear golden brown. Please watch your oven because all ovens are different.
Let cool for 15 minutes in the cake pans. To remove from pans, run a dull knife (careful not to scratch/damage the side of the pans) around the edge of the pans to loosen the cakes. Then place a plate or cooling rack on top and quickly invert. Let cool completely before frosting.
Store cake in the refrigerator for 3-4 days.