In a medium bowl, mix graham cracker crumbs, melted butter, and sugar until well combined. Press mixture firmly into the bottom of a 9-inch springform pan. Chill in the refrigerator while preparing the filling.

In a large bowl, beat the softened cream cheese until smooth and creamy. Add powdered sugar and vanilla extract, and beat until fully incorporated.

In a separate bowl, whip the heavy cream until stiff peaks form. Gently fold the whipped cream into the cream cheese mixture until no streaks remain.

Spread the filling evenly over the chilled crust. Smooth the top with a spatula. Refrigerate for at least 4 hours, or preferably overnight, until set.

Before serving, arrange sliced strawberries on top of the cheesecake. Brush with warmed strawberry jam for a glossy finish.