Like all sponges this has no fat outside of what you find in eggs and is baked in an ungreased pan. From what I read it's very close to an Italian Sponge Cake. This recipe just tickles me. I call it an honest cake. It is the flavor of sugar, eggs and flour. It is such a beauty, and easy to make with a stand mixer. The one caveat is to allow time for this one. The syrup mixture needs time to cool. The cake needs to cool in the pan as well. This isn't a rush home and toss it in the oven kind of cake, but you know taking TIME is the secret element that no one discusses. Many people tout getting things accomplished in as little time as possible. Not me and not this cake.   

Water Cake

12 ounces sugar

4 ounces water

5 whole eggs

2 egg yolks

6 ounces flour

Preheat oven 350 degrees. Prep a 10 inch springform pan by NOT greasing it, but cutting a disc of parchment to fit the bottom. 

I'm using weights here because I used weight to make the cake. If you don't have a scale for baking, you sincerely should. 

In a small pot combine the sugar and water, bring to a boil and simmer until the sugar is no longer granular. Brush down any crystals clinging to the sides of a pan with a pastry brush dipped in water. Let cool. 

In a bowl of a stand mixer gently combine the eggs. In a slow stream while the mixer is on low, add the sugar syrup. Once it's all combined, scrape the sides of the bowl and whip on medium-high for 5 to 8 minutes, or until the volume is doubled. Remove the bowl from the stand and gently mix the flour in by hand. Be careful not to deflate the eggs and don't be slow to getting the cake to the oven once it's poured into the pan. 

Bake for 30-35 minutes until a tester comes out clean. Cool in the pan 15 minutes; while it is still warm run a knife around the cake, loosening it from the pan. Allow it to cool completely. 

It's a sturdy cake and can handle being flipped to remove the parchment from the bottom. Serve with anything. It's delicious.