Wash the two oranges, then place them in a small saucepan and cover with water. Bring to the boil and simmer for 1 hour. Remove from the water and set aside to cool slightly.

When cooled, cut them half and remove the pips. Put in a food processor or blender with the Grand Marnier and blitz for 10 seconds.

Place the eggs and sugar in a large bowl and whisk until the sugar has dissolved and the eggs are pale in colour. Fold in the orange and Grand Marnier puree, polenta, almond meal, and baking powder.

Line the base of a 25 cm – 10 inch springform cake tin with baking paper and pour the mixture into it.

Bake in a pre-heated oven at 180°C – 355°F for 35–40 minutes. Cool in the tin and set aside.

To prepare the syrup, pour the sugar and 2 tablespoons of water into a small saucepan. Heat slowly until the sugar melts and caramel-coloured bubbles appear. Pour in the orange juice and the Grand Marnier and bring to the boil. Add the cinnamon stick and cook for 15 more minutes, or until the liquid has reduced by half.

Remove the cooled cake from the tin and place on a serving plate. Using a wooden or metal skewer, make holes all over the top of the cake and pour half of the syrup into the holes. Serve the remaining syrup on the side.