Beat the egg white and salt until stiff, slowly adding 100 g of sugar. Continue beating until the sugar has dissolved and a shiny mass has formed.
Pour the beaten egg white into a piping bag with a medium-sized perforated spout and spray about 12 medium-sized tuffs onto a baking tray lined with baking paper. In a preheated oven (electric cooker: 90 °C/ circulating air: 65 °C/ gas: see
manufacturer) bake for about 1 1/2 hours. Open the oven door and let the meringue tuffs cool down.
Meanwhile drain the beetroot, chop it finely and put it in a bowl with the oil, mash it finely. Add the eggs bit by bit. Mix flour, baking powder, cocoa, remaining sugar and vanillin sugar.
Add to the vegetable puree and mix to a smooth dough. Grease a springform pan (20 cm Ø) and dust with flour. Pour in the dough and bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see
manufacturer) bake for about 40 minutes.
Remove from the oven and leave to rest in the mould for about 10 minutes. Turn out onto a cake rack and let it cool down. Bring cream to the boil in a small pot. Remove from the stove. Chop the chocolate coating. Add couverture and coconut oil to the cream and let it melt while stirring.
Chill for about 10 minutes. Spread the cake except for 1 tablespoon for garnishing. Pour the rest of the chocolate cream into a piping bag with a very small perforated nozzle and garnish the meringue tuffs with dots as faces.
Allow to dry. Garnish cake with meringue tuffs and cut into pieces.