Method

• 1.
  Preheat oven to 180C. Grease and line the base and sides of a 24cm springform cake pan with baking paper, so the paper comes 2cm above the rim of the pan.

• 2.
  Place half the blackberries in a small saucepan over medium heat with lime juice and 2 tbs sugar. Simmer, stirring occasionally, for 10 minutes or until fruit is softened. Pass the fruit through a sieve, pushing down on the solids with the back of a spoon. Set aside to cool completely.
• 3.
  Scatter almonds on a baking tray and toast in oven for 8 minutes or until golden. Whiz the toasted almonds and gingernuts in a food processor until they resemble fine breadcrumbs. Add the melted butter and process until combined. Press the biscuit mixture into base of the pan, then chill for 30 minutes to set.
• 4.
  Meanwhile, beat the eggs, cream cheese, sour cream, cream, vanilla, flour and remaining 1 cup (220g) sugar with electric beaters for 3-4 minutes until smooth and thickened. Add the chocolate and beat to combine.
• 5.
  Pour the cheesecake batter into the prepared pan and tap the pan gently on a flat surface to remove any air bubbles. Pour the cooled blackberry puree over the top in a spiral, then using a skewer, swirl it into the cheesecake batter.
• 6.
  Bake for 1 hour or until almost set in the centre. Turn off oven. Leave the cheesecake in the oven, with the door ajar, for 2 hours or until cooled completely. Place in the fridge for at least 2 hours or overnight to set.
• 7.
  Serve with whipped cream and the remaining 300g blackberries.