Preheat oven to 325F (163C).
Blend the egg whites, apples, and vanilla for about 30 seconds.
Add the rest of the ingredients for the cake and blend for another 30 seconds. Scrape down the sides of the blender with a spatula, if necessary, and blend again until well combined (another 30 seconds or so).
Pour batter into a 7" or 8" square pan, or any baking pan of similar size. (If you are not using silicone bakeware, be sure to line your pan with parchment paper.)
Bake for 20-25 minutes.
Remove from oven and let cool.
Mix maple syrup with cloves, and brush over top of cake.
Enjoy!