Method

• 1.
  Grease a 21cm cake pan (not springform) and line the base with baking paper.
• 2.
  For the sticky oranges, place orange slices in a large, deep frypan and cover generously with cold water. Bring to the boil over high heat, drain, and repeat twice more. Place sugar, orange juice, liqueur and 1 1/2 cups (375ml) water in a saucepan over medium-high heat and stir until sugar dissolves. Bring to a simmer, add orange slices and cook for 20-25 minutes until tender and translucent. Remove from syrup and transfer to a tray. Continue cooking syrup for 10-15 minutes until caramelised and reduced by half. Pour 1/3 cup (80ml) syrup over base of prepared pan, swirling to coat evenly. Carefully arrange orange slices over syrup so they overlap. Set aside.
• 3.
  Place butter and sugar in a stand mixer with the paddle attachment and beat for 3-4 minutes until pale and fluffy. Add eggs one at a time, beating to combine, scraping down sides of bowl after each addition. Fold in flour and ginger, then the marmalade, orange zest and juice and buttermilk. Spoon into prepared pan over the orange slices and smooth top.
• 4.
  Lightly butter a sheet of baking paper a little larger than the cake pan and fold to form a pleat in the centre. Place over the cake pan, buttered side down, and top with a large pleated piece of foil. Using a piece of kitchen string, tie around the top edge of the cake pan to enclose tightly.
• 5.
  Place cake pan in a large saucepan with a lid. Add hot water to come three-quarters up sides of cake pan. Bring to the boil, then reduce heat to low, cover with a lid and simmer, topping up with hot water as necessary, for 2 hours 30 minutes until a skewer inserted in the centre comes out clean. Stand for 30 minutes.
• 6.
  Meanwhile, for the ginger custard, combine cream, milk, liqueur and grated ginger in a saucepan over medium heat. Bring to a simmer, then turn off heat and stand for 30 minutes to infuse.
• 7.
  Whisk yolks and sugar in a heatproof bowl until pale, then whisk in ground ginger. Return cream mixture to a simmer, then strain over the egg mixture, whisking continuously. Return to the pan and place over medium low heat, stirring constantly, for 5-7 minutes until the mixture coats a spoon thickly. Strain into a serving jug.
• 8.
  Carefully invert pudding onto a serving plate and serve with ginger custard.