Prep the pan: Lightly grease a 9-inch springform pan and line the bottom with parchment for easy removal.
Make the crust: Stir graham crumbs, sugar, and salt.
Add melted butter and mix until the texture resembles wet sand. Press firmly into the pan, pushing up the sides slightly. Chill for 20 minutes.
Bloom the gelatin (optional): Sprinkle gelatin over 2 tablespoons cold water in a small bowl.
Let sit 5 minutes. Warm gently in the microwave for 5–10 seconds until just melted, or place the bowl in a mug of hot water. Let cool to lukewarm.
Whip the cream: In a cold bowl, whip heavy cream to medium-stiff peaks.
Do not overbeat. Set aside.
Beat the cream cheese: In a separate bowl, beat cream cheese until smooth. Add powdered sugar, vanilla, lemon zest, and lemon juice.
Beat until creamy with no lumps.
Add gelatin: If using, stream the lukewarm gelatin into the cream cheese mixture while mixing on low. Scrape the bowl well.
Fold in whipped cream: Gently fold the whipped cream into the cream cheese mixture in two additions until fully combined and airy.
Fill and level: Spoon the filling over the chilled crust. Smooth the top with an offset spatula.
Tap the pan lightly on the counter to release air bubbles.
Chill to set: Cover and refrigerate for at least 6 hours, preferably overnight, until firm.
Cook the topping: In a small saucepan, add 1 1/2 cups blueberries, sugar, lemon juice, and a pinch of salt. Cook over medium heat, stirring, until juices release and simmer, about 4–6 minutes. Stir in the cornstarch slurry and cook 1–2 minutes until thick and glossy.
Remove from heat, stir in vanilla, and fold in the remaining 1/2 cup blueberries for fresh pops of texture. Cool completely.
Top and serve: Release the cheesecake from the pan. Spoon the cooled blueberry topping over the surface, leaving a small border if you like.
Slice with a hot, dry knife for clean edges.