Here’s a simple and rustique family recipe to make crumble:
Cover the bottom of a heat-resistant dish with slices of fruit such as apples, pears, or plums.
Stir up some crumbles for the topping (you can use the same recipe for the topping as in Streuselkuchen, but i’d leave out the cinnamon and use brown sugar instead)
Add nuts and put into the oven for about 40 to 45 minutes until slightly brown.