Open the chilled coconut milk cans unshaken. Remove approx. 350 g of firm coconut cream and put it back in the fridge. Put the rest of the coconut milk aside at room temperature. Preheat the oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see
manufacturer). Line the bottom of a square springform pan (24 x 24 cm; alternatively round, 26 cm Ø) with baking paper.
Coarsely grate the chocolate. Sift flour, baking powder and cocoa. Mix with chocolate shavings. Whisk 300 ml room-warm coconut milk, lemon juice, oil, coffee powder and sugar. Add to the flour mixture and mix quickly with the whisk of the mixer.
Smooth the dough in the form.
Bake the cake in a hot oven for about 30 minutes. Remove and immediately sprinkle with rum. Leave to cool in the mould on a cake rack.
Carefully remove the cake from the mould. Cream cold coconut cream and icing sugar with the whisk of the mixer and fold in 100 g of grated coconut. Spread the cream on the cake. Chill for at least 1 hour.
Chop the chocolate coating for the glaze. Heat the rest (approx. 150 ml) of coconut milk at room temperature. Remove from the heat and melt the chocolate coating while stirring. Leave to cool for about 5 minutes. Cut the cake into approx. 18 bars (each 4 x 8 cm).
Spread the casting on the bars. Sprinkle 2 tbsp. grated coconut on top. Let the icing dry.