For orange cake, grease loaf pan and dust with flour. Cream butter in a food processor until fluffy. Gradually add eggs and powdered sugar, then mix in flour and cornstarch until homogeneous.
Preheat the oven to 150°C. Pour the batter into the pan and bake for about 60 minutes, increasing the temperature constantly to 180°C. Check if the cake is done with the help of a test stick.
Turn out the cake and let it cool. Squeeze the oranges and heat them together with the sifted powdered sugar in a pan, stirring constantly, until a homogeneous mixture is formed.
Pour it over the cake. Serve the orange cake.