In a saucepan over medium heat, combine fresh raspberries, granulated sugar, and lemon juice. Stir frequently until the mixture comes to a gentle boil, then dissolve cornstarch in a little water and pour it in, stirring continuously. Simmer the sauce for about 5 minutes until it thickens slightly. Strain to remove seeds and cool completely.

In a medium bowl, mix graham cracker crumbs and melted butter until resembling wet sand. Press into the bottom of small serving cups, creating an even layer. Set aside.

In a large bowl, whip cold heavy cream on medium speed until soft peaks form. Gradually add powdered sugar until stiff peaks form, reserving ½ cup for topping.

In another bowl, beat cold cream cheese until smooth. Gradually mix in powdered sugar, lemon zest, and vanilla extract. Fold in the whipped cream gently until combined.

Layer cheesecake filling into the crust, add raspberry sauce, and repeat layers if desired. Top with reserved whipped cream and garnish with fresh raspberries and mint leaves before serving.