A masterclass in how to turn a simple genoise sponge into something really special. Decorated with chopped nuts and coffee buttercream, these individual cakes are packed with flavour.
Pre-heat the oven to 180°C/160°C/Gas 4. Grease a shallow 18cm square cake tin and line the base with baking parchment.
For the genoise, gently melt the butter in a pan, then set to one side to cool slightly. Measure the eggs and sugar into a large bowl and whisk at full speed until the mixture is pale and mousse-like and thick enough so that a trail is left when the whisk is lifted from the mixture.
Sift the flours together into a bowl. Carefully fold half the flour into the egg mixture, gently pour half the cooled butter around the edge of the mixture and then fold in. Repeat with the remaining flour and butter. Pour the mixture into the prepared tin.
Bake in the oven for 35–40 minutes or until well risen and the top of the cake springs back when lightly pressed with a finger. Leave to cool in the tin for a few minutes then turn out, peel off the parchment and finish cooling on a wire rack.
To make the coffee icing, measure the butter into a small pan and gently heat until the butter has melted. Remove from the heat and stir in the coffee powder until dissolved. Add the icing sugar and beat until smooth and glossy. Set aside to thicken.
For the crème au beurre moka, measure the sugar and water into a small heavy-based pan. Heat very gently until the sugar has dissolved. Bring to the boil then boil steadily for 2–3 minutes until the syrup is clear and forms a slim thread when pulled apart between 2 teaspoons.
Put the egg yolks into a small bowl and give them a quick whisk to break them up. Pour the syrup in a thin stream over the yolks, whisking all the time until the mixture is thick and cold. In another bowl, cream the butter until very soft and gradually beat in the egg yolk mixture. Stir in the coffee essence to flavour. Spoon into a piping bag fitted with a No. 7 star nozzle.
To assemble, cut the cold cake in half horizontally and sandwich the slices together with the coffee buttercream. Trim the edges and cut the cake into 9 equal squares.
Heat the apricot jam in a pan, then pass through a sieve into a small bowl. Brush the sides of the cakes with apricot jam and press the chopped, toasted nuts around the sides.
Pipe tiny rosettes of crème au beurre moka around the top edges of the cakes, piping them closely together so the fondant icing doesn’t run off the top. Then pipe tiny rosettes around the bottom edges of the cakes.
For the fondant icing, beat the fondant icing with a wooden spoon until smooth. Gradually add the water and food colouring to make a coffee-coloured glaze. Carefully spoon the glaze into the centre of the tops of the cakes and leave to set.