Mix nuts, flour, sugar, salt and spices in a big bowl
Cut the cold vegan butter into pieces and kneed it into the dry ingredients
Add the cold water and form a dough-ball
Cover the ball in clingrap and let the dough rest in the fridge for about 30 minutes
In the meantime you can cover the cooking-tin with vegan butter and preheat the oven to 180C
Spread the dough in a 28cm diameter cooking tin and don´t forget to bring it up the sides as well.
Cover the dough with the yogurt-filling and distribute the rhubarb evenly.
Bake the tarte for about 45 minutes. The tarte ist best when it has chilled in the fridge for a while and sprinkle it with some powdered sugar of course. If you like it sweeter in general you can add sugar to the filling.