Rhubarb jam with elderflower
250 g rhubarb
100 ml concentrated elderflower cordial
125 g Dansukker Jam Sugar

Mousse
50 ml water
250 g Dansukker Granulated Sugar
4–5 (135 g) egg whites
5 sheets of gelatine
500 g raspberries (250 g purée)
150 ml whipping cream
100 ml sour cream

Base
4 eggs
170 g Dansukker Superfine Sugar
5 g baking powder
80 g potato flour
60 g plain flour

Meringue cream
8 (220 g) egg whites
200 g Dansukker Granulated Sugar
340 g butter at room temperature
3 g vanilla sugar

Prepare the jam and mousse the day before. Start with the jam. Rinse and slice the rhubarb and combine with the other ingredients in a saucepan. Boil for about 7–8 minutes. Skim off any foam. Blend the rhubarb jam if desired. Pour into warm, thoroughly cleaned jars. Seal. Store in a cool place.

Make the mousse. Bring the water and sugar to the boil. The sugar mixture should be heated to 121 °C. Whisk the egg whites on a low speed. When the sugar mixture reaches 115 °C, whisk on a higher speed. Lower the speed and pour the sugar mixture in a thin stream into the egg whites, while whisking. Continue whisking until it has cooled.

Soak the gelatine in cold water for 10 minutes. Blend the raspberries and sieve to remove the seeds. Heat a little of the raspberry purée in a saucepan and dissolve the gelatine in it. Add the rest of the purée.

Leave to cool. Fold in the meringue and finally the whipped cream and sour cream. Pour almost all of the dough into two silicone trays/discs, 18 cm in diameter. Pour the rest of the mousse into silicone trays with different shapes. These will be used as decoration. Refrigerate overnight and then freeze.

Heat the oven to 175 °C and make the bases. Beat the eggs and sugar until fluffy, about 10 minutes. Sift and fold in the dry ingredients. Gently mix until smooth.

Divide the dough between two greased springforms/cake tins, 18 cm in diameter. Use a spatula to press the dough out to the edges of the tin. Bake in the bottom of the oven for 18-20 minutes. Remove, allow to cool slightly, and turn the bases upside down on a sheet of parchment paper. Allow to cool completely.

Make the cream. While whisking, heat the egg whites and sugar to 65–70 °C in a stainless steel bowl over a water bath, or until the sugar crystals have dissolved. Pour the mixture into a food processor and whisk into a firm meringue. Whisk until the meringue has cooled. Add the butter in small amounts and whisk for a few minutes until the mixture forms a smooth cream. Add the vanilla sugar and stir. Pour into a piping bag with a round nozzle.

Assemble the cake. Slice the bases in two. Place one base on a cake stand, spread jam on top and add one of the mousses. Add the next base and pipe a layer of meringue cream. Spread it out. Add the next base and the second mousse. Place the last base on top. Spread a layer of meringue cream around the cake and refrigerate for 20 minutes. Then pipe small peaks around the cake. Use a palette knife to draw the peaks up. Decorate with fresh berries and any leftover mousse.

Tip: Leave the cake to stand for a while before serving. It will be more moist and the meringue cream will be softer.