Warm the milk in a saucepan lukewarm. Melt 80 g butter at low heat and let it cool down lukewarm. Crumble the yeast and 50 g sugar into the lukewarm milk and stir with a whisk until the yeast has dissolved. Put 500 g flour in a bowl and make a depression in the middle. Pour yeast milk into the middle and mix with some flour from the rim. Cover with flour and let rest for about 15 minutes.
Add salt, 50 g sugar, vanillin sugar, egg and melted butter and knead with the dough hooks of the hand mixer to a smooth dough. Cover and leave to rise in a warm place for about 30 minutes. For the crumbles, chop 200 g butter finely and put it into a bowl. Add 150 g sugar, 250 g flour and 1 egg yolk and knead into crumbles using the dough hooks of the hand mixer. Put the crumbles in a cool place. Knead the yeast dough again with your hands on a lightly floured work surface. Pour onto a greased fat pan of the oven (32 x 39 cm) and roll out evenly. Spread the crumbles on the dough and let it rise for another 30 minutes. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 25 minutes. Take out of the oven and let cool down a little. Mix icing sugar and lemon juice to a thin glaze and fill into a piping bag or freezer bag. Cut off a small corner and spray thin strips onto the cake.
Pour onto a greased fat pan of the oven (32 x 39 cm) and roll out evenly. Spread the crumbles on the dough and let it rise for another 30 minutes. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 25 minutes. Take out of the oven and let cool down a little. Mix icing sugar and lemon juice to a thin glaze and fill into a piping bag or freezer bag. Cut off a small corner and spray thin strips onto the cake. Serve lukewarm or cold. Whipped cream tastes good with it
1 1/2 hours waiting time