200 g butter, at room temperature
270 g Dansukker Fairtrade Cane Sugar
10 g Dansukker Vanilla Sugar
6 eggs (reserve 3 whites for the meringue)
240 g plain flour 
10 g baking powder
Zest of 1 lemon, preferably organic 
200 g fresh rhubarb

Sugar syrup
170 g Dansukker Granulated Sugar
50 ml water

Heat the oven to 175°C on the top and bottom heat setting. Beat the butter, sugar and vanilla sugar until light and fluffy. Add the 3 eggs and 3 egg yolks one at a time while continuing to beat the mixture. Combine the flour and baking powder and fold into the egg mixture. Grate the lemon zest and stir it in. 

Cut the rhubarb into pieces about 1 cm long. 

Line a wide, shallow oven tin with greaseproof paper. Spread the batter out evenly in the tin and spread the rhubarb pieces over the batter. Bake in the lower part of the oven for approx. 30 minutes. Leave to cool completely. 

Heat the sugar and water to a temperature of 120°C. Beat the egg whites until they are stiff. Pour the hot syrup slowly into the egg whites while continuing to whip them vigorously. Beat until the meringue has cooled to room temperature. 

Cut the cake into pieces or pipe the meringue directly onto the cake. Caramelise the meringue using a cook’s blow torch. If you don't have a blow torch, put the cake in the oven for a few minutes on the top heat setting.