Cut the butter in small pieces and crush the almonds.
In a bowl, mix with the tip of your fingers the sugar, butter, almond powder, both flour and crushed almonds. You should have a sandy texture, not a ball of dough.
Film your bowl with plastic wrap and refrigerate for at least 30 minutes.
Preheat your oven to 180C (356F).
Spread the blackberries in a big baking dish.
Bake for 35 minutes or until it has a nice golden color.