. Make the Cheesecake Base:

• Prep Pan: Line the bottom and sides of the springform cheesecake tin with parchment paper.
• Make Crumbs: Break the graham crackers into smaller pieces and process them in a food processor until they form fine crumbs. Alternatively, place crackers in a zip-top bag and crush with a rolling pin.
• Combine: Melt the butter in a microwave-safe bowl or small saucepan. Pour the melted butter into the graham cracker crumbs and mix with a fork until the crumbs are evenly moistened.
• Press into Pan: Pour the crumb mixture into the lined tin. Press down firmly and evenly to form the base. Do not press too hard, or the base may become too dense.
• Chill: Chill the crust in the refrigerator for at least 1 hour (or up to overnight) until firm.

2. Make the Cheesecake Filling:

• Beat Cream Cheese: Ensure the cream cheese is at room temperature for a smooth filling. In a large bowl, using an electric mixer, beat the room-temperature cream cheese briefly to soften it.
• Add Sugar & Flavorings: Add the granulated sugar, vanilla extract, and lemon juice to the cream cheese. Beat on low speed until combined and the sugar has dissolved. Increase speed and beat until smooth and creamy.
• Whip Cream: In a separate, chilled bowl, whip the cold heavy whipping cream with clean beaters until firm peaks form.
• Fold Together: Gently fold the whipped cream into the cream cheese mixture using a rubber spatula until just combined and no streaks remain. Do not overmix.
• Assemble: Pour the cheesecake filling onto the prepared, chilled base and smooth the top with an offset spatula.
• Chill: Chill the cheesecake in the refrigerator for at least four hours, or preferably overnight, until completely firm and set.

3. Make the Blackberry Coulis Topping:

• Blend Berries: Place 2 cups of the fresh blackberries in a tall jug suitable for an immersion blender (or use a regular blender). Blend until smooth.
• Strain: Pour the blended blackberries through a fine-mesh sieve into a small saucepan, pressing gently on the solids to extract the juice. Discard the seeds/solids.
• Cook Coulis: Add the lemon juice, sugar, and cornstarch to the strained blackberry puree in the saucepan. Whisk well to combine, ensuring the cornstarch is dissolved.
• Simmer and Thicken: Bring the mixture to a boil over medium heat, then reduce to a simmer. Simmer for approximately 15 minutes, stirring frequently, until the sauce has reduced and thickened enough to coat the back of a spoon. The coulis will thicken more as it cools.
• Cool and Chill: Remove the coulis from the heat, allow it to cool completely, and then chill in the refrigerator until ready to serve.

4. Assemble and Serve:

• Release Cheesecake: Once the cheesecake is fully chilled and set, carefully remove the sides of the springform pan. Gently peel away the parchment paper from the sides. Use a large, sharp knife to carefully separate the base from the bottom parchment paper and transfer the cheesecake to a serving plate or board.
• Top and Decorate: Pour the chilled blackberry coulis over the top of the cheesecake just before serving. Decorate with the remaining 12 fresh blackberries.
• Serve: Slice and serve chilled.