Panna Cotta: Soak gelatin in cold water.
Bring milk, cream and sugar to a boil. Remove from the heat. Squeeze out gelatine and add to the hot mixture.
Stir in couverture. Carefully mix in mascarpone. Pour through a sieve and divide among ramekins and refrigerate for approx. 3 hours.
In the meantime, knead all the ingredients for the crumble together until crumbles form. Put them on a baking tray covered with baking paper and bake at 170°C until golden brown.
Let cool and spread on the panna cotta before serving.