Make the crust: Crush the biscuits into fine crumbs using a food processor or a zip-top bag. Mix with melted butter until evenly moistened.
Press firmly into the bottom of an 8-inch (20 cm) springform pan. Refrigerate while preparing the filling.
Prepare the blueberry purée (for the filling): In a small saucepan, combine blueberries, sugar, and lemon juice. Cook over medium heat until the berries soften and the sugar dissolves.
Remove from heat and blend until smooth and let cool completely.
Bloom the gelatin: In a small bowl, mix gelatin powder with cold water. Let bloom for 10 minutes.
Make the cheesecake filling: In a large bowl, beat the cream cheese until smooth and creamy. Add powdered sugar and vanilla extract and mix until combined.
Pour in the heavy cream and beat just until soft peaks form. Add the cooled blueberry purée and mix until smooth.
Temper the gelatin: Microwave the bloomed gelatin for 10–15 seconds, just until melted (do not boil). Temper by stirring a few tablespoons of the cheesecake mixture into it, then pour it back into the bowl and mix until fully incorporated.
Pour the filling over the crust and smooth the top.
Chill: Refrigerate (or freeze) for about 1 hour, until set enough to hold the topping.
Make the blueberry topping: In a small saucepan, mix the sugar and cornstarch. Add blueberries, lemon zest, lemon juice, and water. Cook over medium heat, stirring constantly, until the sauce thickens and the blueberries soften, about 5–7 minutes.
Remove from heat and let cool slightly. Spread the topping evenly over the chilled cheesecake.
Final Chill: Refrigerate the cheesecake for at least 6 hours, preferably overnight, until fully set.
Video
Notes
Biscuit/cracker options: Digestive biscuits, graham crackers, tea biscuits, or vanilla cookies all work well. Keep in mind that different brands absorb butter differently, so if the crumb mixture looks dry, add 1 extra tablespoon of melted butter or a splash of milk, just until it reaches a moist, sandy texture.
Gelatin tips: Always bloom gelatin in cold water. Tempering prevents lumps and ensures a smooth texture.
Make-ahead & storage: Store in the refrigerator for up to 4 days. Best served cold, straight from the fridge.
Flavor variations: Swap blueberries for raspberries, blackberries, or mixed berries. For extra freshness, finish with a few fresh blueberries on top.
Pan release tip: Before serving, run a thin knife around the edge of the pan or warm the sides briefly with a kitchen towel dipped in warm water for a clean release.
Serving tip: For clean slices, wipe the knife with warm water and dry it between cuts.