Coarsely chop the peanuts. Roast peanuts and oat flakes in a pan without fat while turning. Sprinkle with 1-2 tsp. sugar and caramelise briefly. Remove.
Stir the quark, milk and vanillin sugar until smooth. Season to taste with approx. 2 tbsp. sugar.
Select the blueberries, wash and drain well. Peel and slice the bananas. Sprinkle with lemon juice.
Fold blueberries, bananas and cranberries, except for 1 tbsp. for sprinkling, into the quark. Arrange the quark in small bowls. Sprinkle with remaining fruit and oatmeal-peanut mixture. Decorate with mint.