Heat the oven to 400°F/200°C. Butter an 8” by 8” baking dish.
Make the grumble topping: Cream together the butter and brown sugar. Cut in the ground almonds and the oats. (You could add some cinnamon and ginger if you like, too, although I prefer it plain.) Set aside.
Toss the fruit with the sugar and flour and tumble into the baking dish
Sprinkle the crumble mixture evenly over the fruit and press to pack it down a bit. Bake until the fruit is soft and the top crisp, about 40 minutes. Let sit about a quarter hour before serving with sweetened, vanilla-flavoured whipped cream.