Peel, wash and roughly grate the carrots. Finely chop the walnuts. Separate 2 eggs. Chill the egg whites. Mix egg yolk, 2 eggs, 200 g sugar, oil and yoghurt in a bowl with the whisk of the hand mixer.
Mix flour and baking powder, stir in quickly. Finally fold in carrots and walnuts.
Grease a box mould (2.7 litres capacity; top: 25 cm long, bottom: 22.5 cm long) and dust with flour. Pour in the dough, smooth it down and bake in a preheated oven (electric cooker: 175 °C/ circulating air: 150 °C/ gas: see
manufacturer) bake for about 1 hour. Remove from the oven, leave to cool in the pan for approx. 30 minutes, turn out and leave to cool on a cake rack for approx. 2 hours.
Beat 3 egg whites until stiff, adding 150 g sugar. Spread the meringue mixture on the cake with a spoon, while lifting up light peaks. Carefully flame the cake with a crème brûlée burner.