Simmer two whole oranges in water for 45 to 60 minutes until very soft.
Preheat the oven to 180°C and grease a 23cm springform cake tin.
Drain the oranges and roughly chop them while removing any pips.
Blend 450g of chopped orange in a food processor to a smooth purée.
Add sugar, eggs, and ground almonds to the processor and blend until smooth.
Spoon the mixture into the prepared tin and bake for 25 minutes.
Cover loosely with foil and bake for another 25 to 35 minutes until a skewer comes out clean.
Heat a frying pan and add butter, orange zest, orange juice, and sugar.
Add the liqueur and brandy then carefully flambé the mixture until the flames die down.
Cook until thickened, stir in the orange segments, and remove from heat.
Serve a slice of cake immediately topped with sauce and a scoop of ice cream.