Orange chocolate cake

I made a cake for a dinner party last Friday. It is from Nigella Lawson's cookbook; Feast.
I have been getting cookbooks from the library and trying out at least one recipe from each cookbook.
This recipe is simple but rich and also somewhat unusual since it is made with ground almonds. If you replace sugar with sweeteners, it would be great for friends who are on a diet...

Here is the recipe...

Ingredients:
2 small oranges
6 eggs
2 cups of ground almonds
1.25 cups of powder sugar
1/2 cup of unsweetened cocoa
1 heaped teaspoon baking powder

Fill up a pot with water and boil the two oranges for two hours (You can do this the day before you bake the cake). The cut the oranges in half and check for seeds. If there is any, clean them up, if not cut the oranges to big chunks and process them in food processor (the whole oranges with skin and everything)

Then add all the other ingredients including eggs (no need to beat the eggs in advance)
Pour into a buttered cake pan and bake 45 minutes at 350. Check with a toothpick if it is done. You may have to bake some more if not done.
Cool off the cake and then take it off the pan.
I served it with a gallop of whip cream. It was very very yummy...