• Place clementines in a pot with cold water to cover, bring to a boil, and cook for 2 hours.
• Drain and, when cool, cut each clementine in half and remove the seeds.
• Finely chop the skins, pith, and fruit in the processor (or by hand, of course).
• Preheat the oven to 375° F.
• Butter and line an 8-inch springform pan with parchment paper.
• Beat the eggs. Add the sugar, almonds, and baking powder.
• Mix well, adding the chopped clementines.
• Pour the cake mixture into the prepared pan.
• Bake for 40 minutes, cover with foil, and bake for an additional 20 minutes, or until a skewer comes out clean.
• Remove from oven and leave to cool on a cooling rack.

Glaze and Topping

• Make a glaze from confectioner's sugar mixed to a paste with lemon juice and a little water.
• Decorate the cake with glaze and sliced oranges or clementines.