Best Ever Orange and Almond Cake

This cake is heavenly! Perhaps the word "cake" is wrong? This is more like a slice of cloud-like orangey bliss. My mother went to a café and said that she had the best ever Orange and Almond cake; and said that I could not beat it. But, being the competitive baker I am, I decided to bake my own in an attempt to beat this "café cake." And when she tasted my creation, I indeed did! It was the best moment (after having boiled oranges for 1 hour and a half and having waited paitently for the cake to cook) to hear that all my work paid off. Usually I would dust the cake with icing sugar, but my mother also demanded icing. You will find a perfect icing accompaniment for this cake as well. I considered calling this a "cloud like cake" because it truly is - almost like mousse - and will be so light that it melts in your mouth. But I do warn you, this is potentially lethal for those of us trying to watch our figures!

Ingredients for Cake
2 large oranges (eg. Navel)
6 eggs, seperated
3/4 cup caster sugar
200g almond meal
1 tsp baking powder

Method for Cake
Wash oranges and place them unpeeled in a pot of boiling water. Let it simmer for 1-2 hours (eg. I did 1 1/2). Then, drain the water and allow the oranges to cool. Cut the base of the orange and remove the pith (white stuff between the rind and the flesh) because this will reduce the bitterness. Blend the oranges in a food processor/blender to a smooth consistency. Preheat your oven to 180 degrees (fan-forced) and prepare a round 20cm deep baking tin. Springform tin's are the most convenient here. Beat the egg yolks and sugar together using an electric mixture until smooth. Please note the egg whites will need to be kept for later use. Add the orange purée and beat. Add the baking powder and almond meal and beat at a low speed until just combined. Beat the egg whites in another bowl until stiff peaks form. Add these whites to the almond batter and fold in gently until just combined. Pour batter into prepared tin and bake for 1 hour and test with a skewer. Dust with icing sugar or the following orange icing.

Ingredients for Icing
60g butter, softened
2 teaspoons grated oranged zest
2 tablespoons orange juice
1 1/2 cups of icing sugar, sifted

Method for Icing
Beat the butter and the zest, then gradually add the juice and icing sugar. Spread over cake and around it's sides. Sprinkle some grated orange zest on the top, this gives the cake an extra dimension, texture-wise.