Let the frozen forest fruits thaw slightly and mix with the fresh berries, flour, sugar and vanilla sugar and distribute in a greased baking dish.
For the crumble mix all the dry ingredients together, then add the egg yolk and melted butter and quickly work into crumble and spread on the fruit. Sprinkle with the sliced almonds or almond flakes and bake for 30 minutes in a preheated oven at approx. 180-200 ° C until golden brown.