Nigella's Old-Fashioned Chocolate Cake

This site translates the quantities into cup measurements.

Cake:
200g plain flour
200g caster sugar
1 teaspoon baking powder
1/2 teaspoon bicarb
40g cocoa powder
175g soft butter
2 large eggs
2 teaspoons vanilla
150ml sour cream

Icing:
75g butter
175g good quality dark chocolate, in pieces
300g icing sugar
1 tbs golden syrup
125ml sour cream
1 teaspoon vanilla

Take everything out of the refrigerator so that all ingredients can come room temperature. Preheat the oven to 180 degrees C. Line and butter two 20 cm cake tins.

Put all the cake ingredients: flour, sugar, baking powder and bicarb, cocoa, butter, eggs, vanilla, and sour cream into a food processor and process until you have a smooth, thick batter. If you want to go the long way around, just mix the flour, sugar and leavening agents in a large bowl and beat in the soft butter until you have a combined and creamy mixture. Now whisk together the cocoa, sour cream, vanilla, and eggs and beat this into your bowl of mixture.

Divide this batter, using a rubber spatula to help you scrape and spread, into the prepared tins and bake until a cake tester comes out clean, which should be about 35 minutes, but it is wise to start checking at 25 minutes. Also, it might make sense to switch the 2 cakes around in the oven halfway through cooking time. Remove the cakes, in their tins, to a wire rack and let cool for 10 minutes before turning out of their tins.

To make this icing, melt the chocolate and butter in a good-sized bowl either in suspended over a pan of just boiled water (but removed from the stove). While the chocolate and butter is cooling a little, sieve the icing sugar into another bowl. Add the golden syrup to the cooled chocolate mixture, followed by the sour cream and vanilla and then when all this is combined whisk in the sieved icing sugar.

You may need to add a little boiling water, say a teaspoon or so, or indeed some more confectioners' sugar, depending on whether you need the frosting to be thiner or thicker. It should be liquid enough to coat easily, but thick enough not to drip off.

Choose your cake stand or plate and cut 4 strips of baking parchment to form a square and sit 1 of the cakes, uppermost (i.e. slightly domed) side down. Spoon about 1/3 of the frosting onto the center of the cake-half and spread with a knife until you cover the top of it evenly. Sit the other cake on top, normal way up, pressing gently to sandwich the two together.

Spoon another 1/3 of the frosting onto the top of the cake and spread it. Spread the sides of the cake with icing and leave a few minutes until set, then carefully pull away the paper strips.