A wonderful coconut and rhubarb tart

I admit that this is basically a re-posting - recipe was already featured on Nami-Nami back in 2007 - but it's been a while and I've tweaked the recipe during those years. Hope you'll forgive me :) I liked the original version quite a bit, but think this modified one is even better. Curiously, I've halved the amount of coconut. If you let it cool completely before tucking in - preferably overnight - it's still immensely coconut-flavoured, yet delicately letting the rhubarb shine as well. Double the coconut - and it's all too sweet and just not right..

So here you go, Rhubarb and Coconut Tart, version 2012.
(Rabarbri-kookosekook)
Serves 8

Crust:
180 g all-purpose flour (300 ml)
2 Tbsp caster sugar
a pinch of salt
100 g cold butter, cubed
1 egg

Filling:
300 g rhubarb, chopped into 1-2 cm chunks

Topping:
75 g butter, softened
170 g caster sugar (200 ml)
1 tsp vanilla sugar or extract
250 g plain yogurt or sour cream
2 eggs
100 g unsweetened shredded coconut

Start with the crust. Sift flour, sugar and salt into a bowl. Add the butter and pinch until crumbly. Add the egg, combine the pastry quickly. Wrap into a clingfilm and place into the fridge for 30 minutes to rest.
Butter a 24 cm loose-bottomed cake tin. Roll out the pastry on a lightly floured surface, making the circle about 34 cm in diametre, then line the bottom and the sides of the cake tin with the rolled-out pastry.
Blind bake at 200 C/400 F for 10-15 minutes until lightly golden.
Meanwhile,  cream the butter, sugar and vanilla until combined. Add the yoghurt/sour cream, eggs, and coconut.
Cut the rhubarb into chunks.
Take the pre-baked tart shell out of the oven, spread rhubarb on top.
Spoon the coconut topping over the rhubarb, smoothing out the top.
Return to the oven for about 30-35 minutes, until the tart is lovely golden brown.

Cool (a little or completely) and cut into slices to serve.