Preheat oven to 180ºC. Line the base of a 22cm cake pan with baking paper and grease the sides.
Place kumquats 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're not going to use a food processor to mix the cake, prep the cooled kumquats by whizzing them in a blender.
In a food processor, mix all the cake ingredients, including the kumquats, until smooth. You can mix by hand if you wish: start by creaming the sugar and butter together then add the whisked eggs, then kumquats, then the flour, baking powder and almonds.
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 syrup ingredients in a small pan and simmer for 5 mins.
When cake comes out of the oven, 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.