In a large mixing bowl using a hand mixer, beat the cream cheese and granulated sugar together until smooth and creamy with no lumps.
Add peanut butter and vanilla extract. Mix until fully incorporated.
Add the sour cream and blend on low speed until just combined. Set aside.
In a separate mixing bowl, pour in the cold heavy cream. Begin whipping on low speed, then gradually increase to medium speed as it starts to thicken.
Once the cream thickens slightly, slowly add the confectioners’ sugar. Continue beating until stiff peaks form. (Stiff peaks stand straight up when the beaters are lifted.)
Using a rubber spatula, gently fold the whipped cream into the peanut butter mixture. Continue folding until the mixture is smooth and no streaks of white remain.
Pour the cheesecake filling over the chilled crust. Use a spoon to smooth the top evenly.
Spoon small dollops of strawberry jam over the top. Use a butter knife to gently swirl the jam into the cheesecake, creating a marbled effect.
Refrigerate the cheesecake for at least 6 hours, or ideally overnight, until fully set and firm.
Once chilled and set, lift the cheesecake from the pan using the parchment paper overhang. Cut into bars and serve chilled.