I always make this lovely cake for my son's birthday. Like most cakes you can make this in a variety of ways, as a layer with frosting or cupcakes, or like I did, as a bundt.
Grate 2 oranges. Chop the zest. Melt 1/2 cup of butter (half a stick) over low heat. Add 3/4 cup of superfine sugar, and juice from one orange. Beat in 2 eggs, 1 cup of flour, 2 teaspoons of baking powder, and add the zest. Bake at 425 degrees for 10 minutes, then turn down to 350 degrees for 20 minutes for a conventional cake, or ten minutes for bundt. Cool.
Sift 1 cup of confection sugar and juice from other orange into pan. Heat until sugar melts, then spread on top of cake.
I decorated mine with flowers. My son did not like it but I thought it was pretty!