Heat the oven to 180°C. Butter a square baking tin (20 x 20 cm).
Melt the chocolate and butter au bain-marie (in a bowl on top of a pan with hot water, the bottom of the bowl should not touch the water).
Open de cardamom pods and take out the black seeds. Powder the seeds.
Add the powdered seeds, the orange zest and juice to the chocolate. Take the bowl off the pan and put it down.
Beat the eggs and sugar until airy. Using a sieve, add the flour and cocoa powder to the eggs. While carefully stirring, add the chocolate. Spoon the batter into the baking tin and bake in the oven for 20-25 minutes.
Cut the oranges in half. Cut the halves into thin moon-shaped slices.
Bring the water and sugar to a boil and add the oranges. Boil for 10 minutes. Turn down the heat and let it simmer for 30 minutes. Take out the oranges and strain using a sieve. Keep the orange syrup.
Whip the cream and sugar until airy. Flavour with cinnamon.