Preheat oven to 160° Line a 22cm cake tin (spring) with baking paper. Put nuts and biscuits in a food processor and grind until coarse. Add butter and mix well. Press into base and sides of prepared tin. Freeze for 30 minutes or until firm.
Put sugar, cream cheese and sour cream in a food processor and mix until smooth. Add eggs, vanilla, and half the flour and mix until smooth. Pour into the prepared biscuit base from before.
Put the remaining flour in a bowl. Add berries as coat. Scatter them on top of the prepared cheesecake. Bake for 1 ½ hours or until it becomes firm. Put on side to rest and cool. Remove from cake tin.
Put lemon juice and jam in a small saucepan and boil, then strain onto the top of the cake. Refrigerate until set. Serve topped with fresh berries.