Preheat the oven to 180°C (160°C fan).
Grease and line a 20cm round cake tin.
In a large mixing bowl, cream together the butter and caster sugar until light and fluffy.
Beat in the eggs, one at a time, adding a little flour with each egg to prevent curdling.
Sift in the remaining flour and cocoa powder, and fold into the mixture until well combined.
Stir in the dissolved coffee and chocolate chips until evenly distributed.
Pour the batter into the prepared cake tin and smooth the top with a spatula.
Bake in the preheated oven for 35-40 minutes, or until a skewer inserted into the centre comes out clean.
Remove the cake from the oven and allow it to cool in the tin for 10 minutes before transferring to a wire rack to cool completely.
To make the chocolate cream, heat the double cream in a small saucepan over low heat until it begins to simmer.
Remove the cream from the heat and add the finely chopped dark chocolate. Stir until the chocolate is fully melted and the mixture is smooth.
Allow the chocolate cream to cool slightly, then spread it over the top of the cooled cake.
Let the chocolate cream set before serving.
