Start by preheating your oven to 350°F (175°C). Grease and line two 8-inch round cake pans with parchment paper.
Break the dark chocolate into pieces and place it in a heatproof bowl. Add the instant coffee granules to 1 teaspoon of hot water and stir until dissolved. Pour the coffee mixture over the chocolate and melt it gently using a double boiler (bowl over a pot of simmering water) or in the microwave in short bursts. Once melted, set it aside to cool slightly.
Separate the eggs, placing the yolks in a large bowl and the egg whites in a separate bowl. Whisk the egg whites until stiff peaks form. In another bowl, whisk the egg yolks with the sugar until pale and fluffy.
Stir the cooled melted chocolate into the egg yolk mixture. Then, gently fold in the almond flour. Next, carefully fold in the egg whites, being careful not to deflate them. Mix until just combined.
Divide the batter evenly between the two cake pans. Bake for 25–30 minutes or until a toothpick inserted into the center of the cake comes out clean. Once baked, let the cakes cool in the pans for 10 minutes, then transfer them to wire racks to cool completely.
In a saucepan, heat the apricot jam until it becomes slightly runny. Set it aside. In a separate heatproof bowl, melt the 8 oz (225g) of dark chocolate and butter over simmering water or in the microwave. Stir until smooth and glossy, then let it cool for a few minutes.
Place the first cake layer on a serving plate. Spread a thin layer of the apricot jam on top. Then, spoon the chocolate frosting over the jam, spreading it evenly. Place the second layer of cake on top, and cover the entire cake with the remaining frosting.
If you like, you can garnish the cake with chocolate shavings, fresh fruit, or edible flowers to give it a beautiful finishing touch.
