How to make zucchini cake with blackberries and crumble topping

• Mix the grated zucchini (I grated it with the skin on coarse holes) with buttermilk and lemon juice.
  300 g grated zucchini (with skin), 120 ml buttermilk, 3 tablespoons lemon juice
• Cream the butter with sugar until fluffy and white.
  200 g butter, 200 g sugar
• Add eggs one by one and mix briefly after each addition.
  3 eggs
• Add the flour mixed with baking powder and baking soda in portions and mix briefly - the mixture will be thick - if it's too thick, you can add a little milk.
  500 g wheat flour - all-purpose, 1 teaspoon baking soda, 1 teaspoon baking powder
• Add the zucchini with buttermilk and mix with a spoon.
• Transfer the dough to a pan measuring approximately 25/38 cm.
• Spread Stovit Blackberry Jam on top.
  2 jars Jam
• Prepare the crumble topping - mix flour with sugar and butter - crumble with your fingers.
  150 g wheat flour - all-purpose, 100 g sugar, 80 g butter
• Sprinkle the crumble topping over the cake.
• Bake at 180 degrees (top/bottom heat) for about 30-35 minutes - until a dry stick comes out clean.