Whisk 500 ml of the milk with the wheat flour, 50 g cornstarch, vanilla sugar, and 100 g sugar until completely smooth.

Bring the remaining 1 l milk to a gentle boil in the large saucepan over medium heat.

Pour the flour mixture into the boiling milk and whisk continuously over low heat until very thick.

Remove the thick cream from the heat and stir in 90 g butter until melted.

Leave the milk cream to cool until warm, stirring once or twice to prevent a skin from forming.

Combine the raspberries and 120 g sugar in the small saucepan and heat until the berries break down into a thick sauce.

Mix the remaining 9 g cornstarch with the water, then stir it into the raspberry sauce.

Cook the raspberry filling for 1 to 2 minutes until thick, then let it cool until warm.

Grease the baking sheet with the remaining butter and cover its surface generously with about 200 g desiccated coconut.

Pour the warm milk cream over the coconut and spread it into an even layer.

Spread the cooled raspberry filling evenly over the milk cream.

Chill the dessert for at least 120 minutes until firm enough to cut.

Cut into rectangles and roll or fold each portion into a triangle.

Sprinkle the finished pieces with the remaining desiccated coconut before serving.