- Preheat the oven to 356F (180C), line the baking tin with parchment.
- Mix the flour, sugar, baking powder, add cold butter in cubes and crumble with your hands or using a paddle attachment into small crumbs, add half the egg and mix again, not achieving uniformity, the dough looks like wet crumbs.
- Put 2/3 of the crumbs into the tin, press.
- Mix the berries without defrosting with sugar,starch and ground cardamom; spread over the crumb layer.
- Sprinkle the remaining crumbs on top.
- Bake at 356F (180C) for about 30-40 minutes, until golden brown.
- Cool and cut into squares.