Prepare the Crust:

• Mix crushed chocolate biscuits with melted butter until well combined.
• Press the mixture firmly into the bottom of a springform pan to form an even layer.
• Chill in the refrigerator for 10 minutes.

2. Make the Cheesecake Filling:

• In a large mixing bowl, beat cream cheese and sugar until smooth and creamy.
• Add eggs one at a time, mixing well after each addition.
• Stir in vanilla extract and sour cream until fully incorporated.
• Pour the mixture over the chilled crust.

3. Bake the Cheesecake:

• Preheat the oven to 160°C (325°F).
• Bake the cheesecake for 50–60 minutes or until the center is set but slightly jiggly.
• Remove from the oven and let cool to room temperature. Refrigerate for at least 2 hours.

4. Prepare the Blueberry Topping:

• In a saucepan, cook blueberries and sugar over medium heat until the blueberries release their juices.
• Add the dissolved cornstarch and stir continuously until the mixture thickens.
• Remove from heat and let cool completely.

5. Assemble and Decorate:

• Spread the cooled blueberry topping evenly over the cheesecake.
• Drizzle with chocolate ganache and garnish with fresh blueberries for an elegant finish.

6. Chill and Serve:

• Refrigerate the cheesecake for at least 4 hours or overnight for best results.
• Slice and serve chilled.