Quark Streuselkuchen
Who doesn’t love a streusel cake? Lots of tart fruit, possibly a creamy filling, and that moreish, sandy crumb on top.
This version uses Quark as its creamy middle and, where many recipes ask for a pastry base, this simplifies things by using the streusel on the bottom AND top.
I used a standard streusel recipe from baking school that is easy to scale (equal parts butter and sugar, double flour), and played around until I found a good ratio for the creamy filling.
As it’s currently the season, I’ve used rhubarb, but you can also use other fruit such as apricots or even frozen raspberries.
Rhubarb topping:
250 g rhubarb
1 tbsp sugar
Streusel base and topping:
150 g butter
150 g sugar
300 g flour
2 tsp cinnamon
1 tsp salt
Quark filling:
2 eggs, separated
1 tbsp cornstarch
250 g half-fat quark
100 g sugar
1 tbsp vanilla paste or extract
zest from one lemon
300 ml whipping cream
Preheat oven to 180 C / 350 F / gas mark 4.
For the rhubarb topping:
Chop the rhubarb into small pieces and mix with sugar in a small bowl. Set aside.
For the streusel base and topping:
Melt the butter over medium heat, then let cool slightly.
In a medium bowl, whisk together the sugar, flour, cinnamon and salt. Pour in the melted butter and stir until you get small streusel-sized clumps.
Line the bottom of a 24 cm (9 inch) springform pan with parchment, then press in two thirds of the streusel mixture, making sure there are no holes.
Reserve the remaining streusel for topping.
For the quark filling:
In a large bowl, whisk the cornstarch into the egg yolks, then whisk in the quark, sugar, whipping cream, vanilla and lemon zest.
Using a medium bowl and an electric mixer, whip the egg whites until they are stiff. Fold them into the yolk mixture.
Assembly:
Spread the quark filling over the base, smoothing the top.
Place the fruit on top, leaving the liquid that has drained in the bowl.
Top with the remaining streusel.
Bake for about an hour or until the topping is browned and the filling is only just slightly wobbly.
I initially used a fluted tart pan that was a tad too small (see pictures above), and there was a bit of overflow. Subsequently I used a 24 cm (9 inch) springform pan and had better results.
If you are using frozen raspberries, there is no need to defrost, just toss with a little sugar and place on top of the Quark filling.
For apricots, simply chop and place on top of the Quark filling, only adding sugar if they are very sour.
I used a half fat Quark Halbfett Quark / Séré demi-gras / Quark mezzo grasso, which is about 20% fat. More on Quark here (plus tips on availability in other countries).
If at any point during the baking you have the feeling the crumble top is getting a bit too brown for your liking, just pop some foil over top.
