Preheat the oven to 360°F, with top and bottom heat.
Put the flour, brown sugar and ground almonds in a bowl. Mix everything. Dice the cold butter and add to the bowl. Mix well with your hands, crushing and spreading the butter until obtaining a compact dough. Set aside.
Wash and dry the raspberries. Put in a bowl and add the juice of half a lemon. Stir well. Add powdered sugar and mix well.
Put a base of jam in the baking pan and spread the raspberries over it, covering the whole baking pan. After adding the raspberries, cover with the crumble dough made in step 1.
Bake for about half an hour and check every once in a while (check first at 15 minutes, not all ovens are the same). Take the raspberry crumble out of the oven once the topping is brown.