In a medium bowl, combine graham cracker crumbs, melted butter, and sugar. Stir until everything is mixed evenly. Spoon a small amount of the crust mixture into the bottom of serving glasses or jars, pressing down gently to form a firm base.

1. In a large bowl, beat softened cream cheese and powdered sugar until smooth. Add vanilla extract and lemon juice (if using) and mix well. In a separate bowl, whip heavy cream until stiff peaks form. Gently fold the whipped cream into the cream cheese mixture until smooth.
2. Layer the cheesecake filling over the graham cracker crust in your serving glasses, smoothing the mixture with a spatula. Add another layer of graham cracker crust if you prefer more crunch.
3. For the strawberries, if desired, toss them with sugar to macerate and enhance their sweetness. Let them sit for 10-15 minutes to release juices. Spoon the strawberries on top of the cheesecake layer.
4. Refrigerate the parfaits for at least 2 hours to allow the flavors to meld. Before serving, garnish with extra fresh strawberries and a sprinkle of crushed graham crackers.