Heat the oven to 180°C/160°C fan/gas 4. In a food processor, use the pulse button to break up the cake into crumbs (or rub the cake in a mixing bowl gently between your fingers to make crumbs).
Using an electric hand mixer or wooden spoon, beat the butter and sugar in a large mixing bowl until fluffy. Slowly add the beaten eggs a little at a time, whisking after each addition, until incorporated.
Sift the baking powder with the flour into the cake batter and mix, along with the cake crumbs, grated orange zest and juice, until well combined. Spoon the batter into the prepared tins.
Bake for 25 minutes until the cakes look well risen and a skewer pushed into the centre comes out clean. Cool for 10 minutes, then turn out.
Meanwhile, make the mulled wine syrup. Bring the ingredients to the boil and simmer for 5 minutes until slightly thickened. Spoon evenly over the puddings until soaked (discard the flavourings).