I have this one from an old Italian cake book by Bimby (it's not really boiled, just warmed, though):
One well-washed whole orange
2 1/2 MC of sugar
3 eggs
1 MC cooking oil
400 g flour
1 sachet baking powder (that's 16 g; I'd use just 2 tsp)
1 1/2 MC orange juice.
First put orange (cut into pieces) and sugar in
and mix at turbo speed until smooth, then use speed 3 at 50ēC for 1 minute. Add oil and eggs, work on turbo 1-2 minutes. Turn speed to 5 and add remaining ingredients (mix only till blended with rest). Bake at 180° for 30\40 minutes.