Strawberry Rhubarb Cake

Ingredients

4large eggsat room temperature
¾ cup150 ggranulated sugar
2 tspvanilla sugar1 packet = 2 tsp (8 g). Sugar flavored with vanillin (artificial vanilla), sold in small packets of about 8 g. In the US use 1 tsp vanilla extract plus 2 tsp sugar for each 8 g packet; in the UK, vanilla sugar sachets, or 1 tsp vanilla extract plus 2 tsp sugar per sachet.
1 pinchsalt
¾ cup plus 1 tbsp100 gall-purpose flourIn German recipes plain flour means soft wheat flour Type 405 unless stated otherwise. In the US use all-purpose flour; in the UK, plain flour.
5 tbsp40 gcornstarchIn German recipes this starch means cornstarch unless stated otherwise. In the US use cornstarch; in the UK, cornflour.
1 tbsp15 gunsalted buttermelted. German butter is unsalted and has about 82 percent fat. In the US use unsalted butter (European-style unsalted butter is closest); in the UK, unsalted butter.

7 oz200 grhubarbpeeled
6 tbsp80 ggranulated sugar
2 tspvanilla sugar1 packet = 2 tsp (8 g). This one is sugar flavored with real vanilla; in the US use 1 tsp vanilla extract plus 2 tsp sugar for each 8 g packet; in the UK, vanilla sugar sachets from the baking aisle, or 1 tsp vanilla extract plus 2 tsp sugar per sachet.
7 tbsp100 mlwater
1 tbsp10 gagar-based gelling powderWeigh it if you can. A plant-based gelling powder made with agar; it has to be boiled briefly to set. In the US and the UK use agar agar powder, using the amount on its package because strengths vary.
3 ⅓ cups800 mlheavy creamwell chilled (!). German cream for whipping has about 30 to 32 percent fat. In the US use heavy cream or heavy whipping cream; in the UK, whipping cream (double cream also works but whips faster, so watch it).

1 ¼ cups300 mlheavy cream
1 packetwhipped cream stabilizerA packet of modified starch and sugar that keeps whipped cream firm; one packet is used for about 1 cup (250 ml) of cream. In the US use whipped cream stabilizer powder (sold online and in some baking aisles), or about 1 tbsp nonfat dry milk powder per cup of cream; in the UK, cream stabiliser powder (sold online), or a spoonful of mascarpone whipped in with the cream.
2 tspvanilla sugar1 packet = 2 tsp (8 g)
strawberries
pistachios

Preheat the oven to 350°F (170°C) convection (fan). Line the bottom of a springform pan with parchment paper.
Beat the eggs, salt, sugar & vanilla sugar for about 10 minutes. If you like, you can separate the eggs instead: beat the egg whites with these ingredients until stiff, then let the yolks run in briefly with the mixer going.
Mix the flour & cornstarch, sift them over the egg mixture and fold them in with love, drizzling in the melted butter as you go.
Pour the batter into the pan and bake on the middle rack of the oven.
After baking, let the sponge cool in the pan.
Once the sponge has cooled, release it from the pan and cut it in half horizontally.
Set the springform ring back around the bottom layer. If you have one, now place an acetate cake collar around the sponge layer as well.
Slice the strawberries and arrange them in the springform pan.

Wash the strawberries, remove the green tops and dice them.
Peel the rhubarb, cut it into thumb-sized pieces and cook it with the water, sugar & vanilla sugar for a few minutes.
Add the agar-based gelling powder and bring everything back to a boil for two minutes, stirring, then let it cool until the mixture is lukewarm.
Whip the cream until stiff and fold it into the rhubarb mixture together with the strawberries.
Spread about ¾ of the filling into the pan, place the top sponge layer on it and spread the rest of the cream over it, then chill for at least three hours.

Whip the cream, sprinkling in the vanilla sugar and whipped cream stabilizer as you go, then transfer it to a piping bag and pipe rosettes on top.
Decorate the cake with strawberries, rhubarb and pistachios.

From German Pastry Chef. Full recipe with photos: germanpastrychef.com/recipes/strawberry-rhubarb-cake/