This cake is a combination of a couple of recipes... A marmalade loaf cake from Nigel Slater's "The Kitchen Diaries", that I've made a few times before, with it's original orange icing drizzled over the top, and a cake called "Nigella's Clementine Cake" from the Green & Black's recipe book.
The Nigella cake is wonderful, but involves boiling 5 clementines for 2 hours, before cooling and pulping them. This puree is then added to other ingredients, including 6 eggs and 250g ground almonds, -so it's a costly cake, both in terms of time and money.
Last time I made Nigel's marmalade cake I realised that the flavour was similar to Nigella's, without all the clementine-pulping, so I thought I'd experiment with the Green & Blacks topping. This involves covering the top of the cake with a grated or finely chopped bar of dark chocolate as soon as it comes out of the oven, so that it melts and then solidifies as the cake cools. The ideal chocolate would be Green & Blacks Maya Gold, but normal plain chocolate works well enough. It's tricky to cut the cake neatly once the chocolate has cooled (see photo!), but the crisp chocolate crust perfectly complements the soft, slightly-bitter, orange-flecked cake underneath.
175g butter (or Vitalite in my dairy-free-ness)
175g caster sugar
75g marmalade (or "orange jam", as Westboy calls it)
175g self-raising flour
100g dark chocolate
Set the oven to 180C/Gas4.
Line a loaf tin* (25cmx11cmx7cm).
Beat the butter and sugar until pale and fluffy.
Gradually add the eggs, beating thoroughly between each addition.
Beat in the marmalade and the grated orange zest.
Fold in the flour.
Gently stir in the juice of half the orange.
Spoon the mixture into the lined tin, smoothing the top.
Bake for 40 minutes, checking after 35 minutes with a metal skewer.
Remove from the oven and immediately sprinkle the grated or finely chopped chocolate over the top of the cake while still in the tin.
Leave to cool completely in the tin.
(The original recipe omitted the chocolate, but used 2 tablespoons of orange juice mixed with 100g icing sugar to make a runny frosting, which was drizzled over the cooled cake)