Wash apples, grate dry, quarter and core them. Cut the fruit flesh into pieces, sprinkle with lemon juice. Knead ground nuts, flour, butter, sugar and vanilla sugar until crumbly. Grease a casserole dish (26 x 20 cm) and spread apple pieces on top.
Cover with the nut crumbles. Bake in the preheated oven (electric cooker: 175° C/ convection oven: 150° C/ gas: level 2) in the lower third for about 40 minutes, remove and sprinkle with flaked almonds. Decorate crumble with apple slices and lemon balm. Goes well with walnut ice cream