5-6 clementines (about 375g total weight)
250g ground almonds
1 heaped teaspoon baking powder
Put the clementines in a pan with some cold water, bring to the boil and cook for 2 hours. Drain and, when cool, cut each clementine in half and remove the pips.
Put the clementines – skins, pith, fruit and all – in a blender and blitz to a purée.
Beat the eggs and add them to the ground almonds, baking powder, flour and sugar. Mix well, stirring in the clementine purée. You will end up with a wet, pale orange batter.
Preheat the oven to gas mark 5.
Butter and line a 20cm springform tin.
Pour the cake mixture into the prepared tin and bake for an hour, when a skewer will come out clean. You might have to cover with foil or greaseproof after about 40 minutes to stop the top burning. Remove from the oven and leave to cool, on a rack, but in the tin.
Turn the cake out onto a plate. This is lovely as it is, with some vanilla ice cream, whipped cream or mascarpone and it can also be iced or given a coating of plain chocolate ganache.