It's a Nigella recipe from How to be a Domestic Goddess.
Snow-Topped Spice Cake
4 large eggs, separated, plus 2 extra large egg whites
125ml vegetable oil
125ml water
2 tbsp runny honey
200g dark muscovado sugar
75g ground almonds
150g plain flour
2 tsps baking powder
1 tsp bicarbonate of soda
pinch of salt
1 tsp ground ginger
1 tsp cinnamon
1/2 tsp all-spice
1/4 tsp ground cloves
zest of 1/2 an orange
100g caster sugar
250g royal icing sugar
Preheat the oven to 180c.
Whisk together the yolks and oil, then add the water, honey and dark muscovado sugar. Add the almonds, flour, baking powder, bicarb, salt, spices and zest, folding in gently. In another bowl, beat the egg whites until soft peaks form and then gradually add the caster sugar. Fold the whites into the cake mixture, and pour into a well buttered 25cm Bundt tin. Cook for 45 minutes, or until the cake is springy on top and beginning to shrink away from the edges. Let the cake cool in its tin on a rack for 25 minutes before turning it out.
When the cake is completely cool, make up the icing. You want it to be pretty thick, or it will disappear into the cake. Drizzle the top of the cake with the icing.
