Prepare the Tin: Lightly grease and line the base of a 23cm (9-inch) springform cake tin with baking parchment. This will make it much easier to release the cheesecake later.

Make the Biscuit Base: Crush the digestive biscuits into fine crumbs. You can do this by placing them in a food processor or putting them in a sealed plastic bag and bashing them with a rolling pin (a great way to get some frustration out!). Pour the melted butter over the crumbs and mix until it looks like wet sand.

Press the Base: Tip the buttery crumbs into your prepared tin. Use the back of a spoon or the bottom of a glass to press them down firmly and evenly across the base and slightly up the sides. Place the tin in the fridge to chill for at least 30 minutes while you make the filling.

Create the Blackberry Coulis: Place the blackberries, caster sugar, and lemon juice in a small saucepan over a medium heat. Cook for 8-10 minutes, stirring occasionally, until the berries have broken down and the sauce has thickened slightly. For a smoother sauce, you can press it through a fine-mesh sieve to remove the seeds. If you prefer a thicker topping, stir in the cornflour slurry and cook for another minute until it thickens. Set aside to cool completely.

Whip the Filling: In a large bowl, use an electric mixer to beat the room-temperature cream cheese and sifted icing sugar together until smooth and creamy. Be careful not to over-beat. Stir in the vanilla extract.

Fold in the Cream: In a separate bowl, whip the cold double cream until it holds soft peaks. Be careful not to overwhip it into butter! Gently fold the whipped cream into the cream cheese mixture using a spatula until just combined. What works best for me is adding the cream in three stages to keep the mixture light and airy.

Assemble the Cheesecake: Spoon the creamy filling onto the chilled biscuit base and smooth the top with a spatula. Now, dollop about half of the cooled blackberry coulis over the top. Use a skewer or the tip of a knife to gently swirl the sauce into the cheesecake filling to create a marbled effect.

Chill to Set: Cover the cheesecake carefully with cling film (without touching the surface) and place it in the fridge to set for at least 6 hours, but overnight is even better for a firm, clean slice.

Serve: Once set, carefully run a thin knife around the edge of the cheesecake before releasing the springform tin. Top with the remaining blackberry coulis and a few fresh blackberries before slicing and serving.