1For the grumble topping: Heat the oven to 400 degrees F/200 degrees C. Butter an 8-by-8-inch baking dish.
2Cream together the butter and brown sugar. Cut in the ground almonds and oats. (You could add some cinnamon and ginger if you like, too, although I prefer it plain.) Set aside.
3For the filling: Toss the fruit with the granulated sugar and flour and tumble into the baking dish.
4Sprinkle 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 15 minutes before serving. If you like, serve with sweetened vanilla-flavored whipped cream.