1. Prepare the Crust:

– In a bowl, mix graham cracker crumbs, melted butter, and sugar (if using). Stir until the crumbs are evenly coated.

– Press the mixture into the bottom of a 9-inch springform pan or pie dish. Use a spoon to pack the crumbs down firmly.

– Place the crust in the fridge to chill while you prepare the filling.

2. Make the Cheesecake Filling:

– In a large mixing bowl, beat the softened cream cheese until smooth and creamy. You can use an electric mixer or a hand whisk.

– Add the powdered sugar and vanilla extract, and continue beating until well combined.

– In a separate bowl, whip the heavy cream until stiff peaks form. Gently fold the whipped cream into the cream cheese mixture, being careful not to deflate the whipped cream too much.

– For an added tangy flavor, stir in the sour cream or Greek yogurt.

– Pour the cheesecake filling onto the chilled crust and smooth the top with a spatula. Refrigerate for at least 4 hours or overnight for best results.

3. Prepare the Blackberry Topping:

– In a small saucepan, combine the blackberries, sugar, and lemon juice. Heat over medium heat, stirring occasionally.

– Once the blackberries start to break down, mix the cornstarch with 1 tbsp of water and add it to the berries. Stir until the mixture thickens, about 3-5 minutes.

– Remove from heat and let the topping cool to room temperature.

4. Assemble the Cheesecake:

– Once the cheesecake has set, remove it from the fridge and spread the cooled blackberry topping over the top of the cheesecake.

– Garnish with additional fresh blackberries if desired.

5. Serve:

– Slice and enjoy! This cheesecake is best served chilled.