Add graham crackers and brown sugar to a food processor and pulse until the crackers are finely ground into crumbs. Slowly pour the melted butter into the food processor while pulsing the graham cracker mixture. Continue pulsing until the mixture resembles wet sand and holds together when pressed between your fingers.
2 cups graham cracker , ½ cup butter, 2 tablespoons brown sugar
In a large mixing bowl, beat the heavy whipping cream, granulated sugar, and vanilla until stiff peaks form. Set aside.
1 cup heavy whipping cream, 2 tablespoons granulated sugar, ½ teaspoon vanilla extract
Place the thawed raspberries and their juices in a blender or food processor and blend until smooth. Strain the puree through a fine-mesh sieve, pressing with the back of a spoon to remove most of the seeds. You should have about ¾ cup raspberry puree.
1 10-ounce bag frozen raspberries, thawed
In a separate large bowl, whisk together the sweetened condensed milk, raspberry puree, fresh lemon zest, and lemon juice until smooth.
1 14-ounce can sweetened condensed milk, 3 tablespoons fresh lemon juice, Zest of 1 lemon
Gently fold the prepared homemade whipped cream (from above) into the raspberry mixture until no white streaks remain.
Prepared homemade whipped cream
Fold in the fresh halved raspberries just until evenly distributed.
1 cup fresh raspberries
Spoon the filling into the prepared graham cracker crust and smooth the top.
Cover and refrigerate for at least 6 hours, but preferably overnight, until the pie is completely set.
Garnish with additional whipped cream, fresh raspberries, lemon zest, or thin lemon slices just before serving.
Additional whipped cream, Fresh raspberries, Lemon zest, Thin lemon slices