For syrupy oranges, simmer orange slices in a small saucepan of water over medium heat to remove bitterness (2-3 minutes). Drain, return to pan, add marmalade and 2 tbsp water, reduce heat to low and simmer until syrupy (1-2 minutes). Arrange in the base of a buttered 2-litre pudding basin and set aside.
Beat butter and sugar in an electric mixer until pale and fluffy (3-4 minutes). Add eggs one at a time, beating well after each addition. Fold in flour, then marmalade, orange rind and buttermilk, and spoon into prepared pudding basin. Smooth top, cover closely with a round of buttered baking paper and seal with foil and string or a lid. Place in a large saucepan, add hot water to three-quarters of the way up sides of pudding basin, cover saucepan with a lid and steam until a skewer withdraws clean (1½-1¾ hours). Top saucepan up with extra boiling water if necessary.
Meanwhile, for thick English custard, combine cream, milk, and vanilla bean and seeds in a saucepan and bring to the simmer over medium heat. Combine yolks and sugar in a bowl and whisk until pale. Pour hot cream mixture over egg mixture, whisking to combine, then return to pan. Stir continuously over low-medium heat until mixture coats spoon (5-7 minutes). Strain into a serving jug.
Invert pudding onto a serving plate and serve hot with thick English custard.
This recipe is from the June 2012 issue of Australian Gourmet Traveller.