Knead the flour, butter, sugar and salt into a crumbly dough. Spread in a greased springform pan and press down a little. Bake in a preheated oven (200 ° C, top / bottom heat) for 20 minutes.
Wash and clean the rhubarb and cut into pieces. Cut open the vanilla pod and scrape out the pulp. Beat the vanilla pulp, eggs and sugar for about 3 minutes until thick and creamy. Then add the creme fraîche and stir in.
Spread the mixture on the hot dough and place the rhubarb on top. Bake at 180 ° C on the second rack from the bottom for 45 - 50 minutes.