For the curd strudel, sift the flour onto the work surface, make a well in the center, add the oil, salt and 75 ml of water and knead everything together to form a smooth dough. Wrap in plastic wrap and let rest for 30 minutes.
For the filling, cream butter and 50 g sugar. Separate the egg, stir the egg yolks into the butter cream. Stir in raisins, rum, curd and vanilla sugar. Whip the egg whites with the remaining sugar until stiff and fold into the curd mixture.
Roll out the strudel dough on a floured tea towel and spread it out very thinly. Brush with the melted butter and spread the curd mixture over two-thirds of the dough.
Lift the tea towel and roll up the strudel, place seam side down in a buttered pan, brush with butter and bake in a 200 degree oven for 30 to 40 minutes.
For the sauce, stir and whisk all the ingredients on a water bath until the sauce thickens. Arrange the strudel with the warm sauce and serve.