Combine graham cracker crumbs, melted butter, and sugar in a bowl until the mixture resembles wet sand. Divide the mixture equally among six serving glasses or jars, pressing firmly to create an even base layer.
In a large mixing bowl, beat the softened cream cheese until completely smooth and free of lumps—about 2 minutes. Add the powdered sugar and vanilla extract, continuing to beat 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 using a rubber spatula, maintaining as much air as possible.
Combine the diced peaches, sugar, lemon juice, and cinnamon (if using) in a bowl. Let sit for 5-10 minutes to allow the peaches to release their juices.
Spoon the cheesecake filling evenly over each cookie base, filling glasses about two-thirds full. Gently tap each glass to settle the filling.
Carefully spoon the peach mixture over each cheesecake layer. Refrigerate for at least 3 hours before serving.