For the pear and plum strudel, knead all the ingredients for the strudel dough into a smooth dough. Shape into a ball, brush lightly with oil and cover with cling film.
Let the dough rest for about 1/2 hour.
For the filling, first mix the sliced pears with the lemon juice, melt 1 tablespoon butter, caramelize 1 tablespoon brown sugar in it and toss the pears briefly in it.
Mix the pears with the finely chopped plums. Mix well the crème fraîche, semolina, sugar and the egg. Preheat the oven to 180°.
Roll out the strudel dough very thinly on a floured surface and cut away the thick edges. Drizzle 1/3 of the dough with a little melted butter and spread the crème fraîche mixture on the remaining dough, then spread the fruit on top.
Roll up the strudel from the filled side. Place the strudel on a baking tray covered with baking paper and put it into the preheated oven.
Bake the pear and plum strudel for about 35 minutes. Serve with powdered sugar before serving.