Grease a mini cheesecake pan with cooking spray or butter. Pulse graham crackers in a food processor until finely ground. Mix with melted butter and press into the bottom of each cavity. Set aside.

In a mixing bowl, beat cream cheese and sugar with an electric mixer until creamy. Gradually add heavy cream, lemon juice, and blackberry preserves, mixing until thickened and fluffy.

Spoon the filling into the crusts, smoothing the tops. Cover with plastic wrap and chill in the refrigerator for at least 4 hours or overnight.

Prepare topping by blending fresh blackberries, sugar, and lemon juice until smooth.

After chilling, remove cheesecakes from the pan and top with blackberry puree and fresh blackberries before serving.