Rhubarb and sour cream tart

Rhubarb season, which seems to have last for a few weeks now in England and in parts of the US, has just began in Estonia (remember, my homeland is at about 58.5 latitude, so quite far up north). During the last week or two, I've already baked two batches of my very favourite rhubarb muffins, cooked a batch of rhubarb kissel (kind of fruit soup), and devoured this spiced rhubarb sheet cake with my family. You'll find all Nami-Nami's rhubarb recipes in this post. Next up? Probably this rhubarb curd from my friend Alanna, and then perhaps Rachel's rhubarb and plum crisp from David's blog? We'll see.

If you do have a good rhubarb recipe suggestion, please share it in the comments!

Today's cake recipe has been another rhubarb favourite for years, and it's also much loved by the readers of my Estonian Nami-Nami site - about 48 people have commented the cake recipe, most of them saying how much they love it :)

Remember - as long as you're using nice and young rhubarb stalks (preferably red-skinned!), there's no need to peel the rhubarb first.  

The idea is from a Finnish Ruokala site (Antin raparperipiiras), but over the years I've modified it considerably to suit my taste, so am happily claiming this as Nami-Nami's rhubarb cake recipe :)

Delicious rhubarb cake with sour cream topping 
(Hõrk rabarbrikook hapukoorega)
Serves eight

Pastry:
100 g butter, at room temperature
85 g caster sugar (100 ml)
50 g sour cream
1 egg
180 g all-purpose flour (300 ml)
1 tsp baking powder

Filling:
250 g sour cream (20% dairy fat)
4 Tbsp caster sugar
1 egg
1 tsp vanilla sugar or extract

Topping:
4 to 5 rhubarb stalks, cut into 5-8 mm slices
demerara sugar, for sprinkling

Preheat the oven to 200 C/400 F. 

Cream the butter with sugar. Stir in the sour cream and egg, then fold in the flour that's been mixed with baking powder. Stir until combined - the pastry should be soft, but not watery. Using your hands, spread the pastry onto the base and sides of a 24 cm (9-to-10-inch) loose-bottomed springform tin.
For the filling, combine all the ingredients. Pour onto the pastry base.
Scatter rhubarb on top, sprinkle with some demerara sugar.
Bake in the middle of a preheated oven for about 30 minutes, until the pastry is golden and the filling is set.Cool in the tin, then carefully remove the tin and transfer the cake onto a serving plate.