200g block dark chocolate, chopped
150g unsalted butter, chopped
1 tablespoon instant coffee granules
1 cup walnuts (100g)
6 eggs, separated
1 cup caster sugar
1 ¼ cups almond meal
100g dark cooking chocolate, chopped
50g unsalted butter, chopped
½ teaspoon instant coffee granules
2 tablespoons icing sugar mixture
Invert base of a 21cm springform pan (base measures 20cm). Grease and line base and side with baking paper, extending paper 4cm above pan edge.
Melt chocolate and butter in a heatproof bowl, sitting over a saucepan of simmering water, stirring until smooth. Remove. Cool for 15 minutes.
Dissolve coffee in 1 tablespoon hot water in a small bowl. Cool.
Process walnuts in a food processor until finely crushed.
Beat egg yolks and sugar in the small bowl of an electric mixer for about 5 minutes, or until thick and pale. Add chocolate and coffee mixtures. Beat until combined.
Transfer mixture to a large bowl. Fold in walnuts and almond meal.
Beat egg whites in the large bowl of electric mixer until soft peaks form. Fold into chocolate mixture, in two batches, until just combined. Pour into prepared pan.
Cook in a moderately slow oven (160C) for about 1 hour, or until just firm to touch. Transfer to a wire rack. Cool cake completely in pan.
To make ganache, melt chocolate and butter in a heatproof bowl sitting over a saucepan of simmering water, stirring until smooth. Remove. Stand for about 20 minutes, or until slightly cooled.
To make icing, dissolve coffee in 1 teaspoon hot water in a small bowl. Stir in sugar until combined.
Remove cake of pan. Transfer cake to a serving plate. Using a spoon, drizzle ganache over top, then drizzle with icing. Stand at room temperature for about 15 minutes, or until set.
Cut into wedges to serve.
TIP! Un-iced cake can be made up to two days ahead. Store in an airtight container in a cool, dark place or refrigerate in hot weather.