Wash the raisins, dab dry, mix with 2 tablespoons of Obstler and set aside. Melt 30 g butter in a frying pan and stir-fry the breadcrumbs briefly in it. Remove from the pan immediately and let it cool down.
Mix sugar, vanilla sugar and cinnamon. Take the strudel dough out of the fridge and let it rest in the package at room temperature for about 10 minutes. Melt 45 g butter and let it cool down a little. Wash, peel and quarter apples and remove the core.
Cut apple quarters into fine slices and mix with lemon juice, grated lemon peel, the sugar mixture and the drained raisins. Place a moistened tea towel on a work surface and cover with a dry cloth.
Unfold 2 strudel leaves. Place one sheet on the cloths, place the 2nd sheet on top, offset by 90°. Spread some melted butter between the two pastry sheets. Repeat this procedure with the other two strudel sheets.
Sprinkle strudel leaves with about 1/3 of the butter crumbs. Mix the rest of the crumbs with the apples and spread them on a good half of the strudel dough. Wrap the strudel sheets at the sides and roll up from the coated side using the cloths.
Place the strudel with the seam side down on a baking tray lined with baking paper. Brush with melted butter and bake in a preheated oven (electric range: 200 °C/ convection oven: 175 °C/ gas: level 3) for 25-30 minutes.
Cut the still warm strudel into pieces, dust with icing sugar and serve with vanilla sauce or whipped cream.