Preheat the oven to 200 degrees top and bottom heat.
Quarter the apples, remove the core, cut the quarters into small cubes and mix immediately with the lemon juice. Peel the ginger and grate finely. Roughly chop the cranberries and mix with the ginger and the apple pieces.
Grease 4 ovenproof dishes (e.g. 200 ml cups) and fill with the apple mixture.
Melt the butte or margarine over low heat, mix with the remaining ingredients to make crumbles and distribute evenly on the apple pieces. Bake the crumble on the middle rack for 20-25 minutes until crispy brown.
Tip: Every oven bakes differently! As a precaution, check the crumble after 20 minutes. Not that it becomes too dark.