The following is a recipe for a simple fat-free cake. You'll need about 4 eggs to make a cake the size of the one in the picture above.
Ingredients: 50g white granulated sugar per egg, 50g self-raising flour per egg. And eggs.
Put the eggs in a bowl with the sugar. Blend, first putting the bowl in a hot (not boiling!) water bath until the mixture gets warm, then take it out and keep blending until it's cooled down to room temperature again. If you're doing this by hand, it'll take about 10 minutes each (so 20 in all), if you're using an electric blender it takes about 5 minutes each (10 in all).
Sift the flour and blend it into the mixture. Immediatly afterwards pour the dough into a tin (that's had its insides buttered with a brush, and then been lightly dusted with flour - this'll make it very easy to get the cake out afterwards). Don't overfill. Don't wait with this step or the flour will raise.
Stick in a pre-heated oven at 175°C for about 45 minutes. It's ready when you can stick a sharp knife in the centre and nothing sticks to it.
Fillings
It has been experimentally proven that putting a layer of dough in the tin, then a layer of cherries (nb: use cherries without pits), more dough, more cherries, then more dough results in the cherries just sinking to the bottom. The cake's also a bit more soggy than usual, but not horribly so. Edible, but not very elegant.
Apple slices work slightly better - they still sink to the bottom but don't all pack together in a single dense layer. Still tasty.