Mix frozen berries with 20 g of sugar. Here I have berries mix.
Mix flour, salt and the rest of the sugar together. Add cold butter. Grind into crumbs. Optionally add crushed nuts. Today I have added oat-flakes.
Put berries into the cake form and sprinkle the crumbs over them like in the photo.
Put into the oven for 20-25 minutes. Baking temperature is 180-200C. Enjoy!
Other example of berry crumble. Strawberries. Nuts added.