Preheat the oven to 310°F, gas mark 3, 160°C (140°C fan-assisted).

Rub some oil on 2 x 20cm (8inch) round cake tins, and line the base with parchment paper.

Dissolve espresso with the boiling water, set aside. Melt the chocolate in a glass bowl over hot simmering water. Then set aside to cool. Beat the eggs and coconut sugar with a electric beater until light and fluffy. Add the vanilla bean paste and coffee mixture. Gradually add the fine cornmeal to the egg mixture.

When the chocolate has cooled, add the mashed bananas. Fold the chocolate and mashed bananas into the egg mixture until combined. Divide the mixture between the two cake tins and bake on the middle shelf for 30 minutes. Remove from the oven and leave to cool in the tins for 10 minutes, then turn out onto a wire rack to cool, then either cover tightly with foil or continue to decorate.

To make the icing, melt the chocolate as above, then slightly cool and stir in the coconut oil and then the cream.

To assemble the chocolate covering, place one half of the cake on your serving platter. Using a palette knife, spread a layer of the chocolate icing on the cake, then sandwich together.

Cover the sides and top of the cake with the icing carefully with a warmed palette knife. Fill in any gaps. The sides/top should be straight and even. Scatter the crushed banana chips around the sides of the cake and decorate the top with chocolate shavings. Allow the cake to sit at room temperature, covered by a cake dome or a large glass bowl, for at least two hours before serving. The flavours will improve and get better with time.