Remove the zest from the orange (should be about 1 tablespoon) and set aside. Make sure you don’t get any of the pith in your zester (that’s the white inside part of the orange which is really bitter). Juice the orange (should be about 1/3 cup), reserving the juice for use in the recipe.
In a bowl, whisk together the flour, baking soda, and salt. Set aside.
In a large bowl, cream the butter and sugar. Add eggs, one at a time, beating into the mixture. Beat in 1/4 cup orange juice (reserve the rest for icing) and yoghurt.
Add the dry ingredients to the wet ingredients. Fold in the orange zest and keep mixing till the mixture is well-blended.
Pour into prepared baking pan. Sprinkle white chocolate chips on top of the batter. If they do not sink in, tap pan gently once on the counter. Bake 20 to 25 minutes until lightly browned and the cake is done. Stick a knife in the centre and if it comes out clean, it’s done.
While the cake is baking, melt orange marmalade and butter in the microwave about 45 seconds. Stir it and then add around a large peg of cognac – good quality cognac.