Preheat oven to 180ºC and line the base of a 22cm cake pan with baking paper and grease the sides.
Place cumquats in a pan and cover with water. Simmer for 10 mins or until soft then cool. If using oranges they will take 20-30 mins. Cut in half and remove seeds.
If you need to grind the almonds, do them first in the food processor, then add remaining ingredients for cake, including the cooked cumquats, skin and all. Mix until smooth, stopping once to scrape down mixture from the sides.
Tip mixture into cake pan and bake for an hour or until a skewer inserted in the middle comes out clean. Ovens vary so start checking after 45 mins.
Meanwhile make the syrup – place all ingredients in a small pan and simmer for 5 mins.
Make holes over the top of the cake with a metal skewer and spoon the warm syrup over as soon as it comes out of the oven. The syrup will be absorbed.
Serve dusted with icing sugar, either warm or at room temperature, with a dollop of thick cream.
