1.
Preheat oven to 180 C / Gas 4. Grease and flour a 20x30cm tin. Sift together flour and baking powder.
2.
Beat the egg whites to soft peaks, then continue beating while slowly adding the sugar until stiff peaks have formed. Fold in egg yolks until evenly mixed, then fold in the flour mixture alternately with the orange juice. Pour cake mixture into the prepared tin.
3.
Bake cake in preheated oven until the top has turned golden brown, and a skewer inserted into the centre comes out clean, about 40 minutes.
4.
When the cake is done, remove from the oven, and use a fork to poke all over the top of the cake, in 2.5cm intervals. In a small bowl, stir together the milk, coconut milk and sweetened condensed milk. Evenly pour the milk mixture over the cake, then sprinkle with desiccated coconut. Chill cake in the refrigerator until cold, about 3 hours.