In a large bowl, using an electric mixer, beat together the room temperature cream cheese, sugar, salt, and vanilla extract until smooth and cream.
Then, in a separate medium size bowl, beat your heavy whipping cream until stiff peaks form.
Proceed to fold the whipped cream into the large bowl with the cheesecake filling, until it has been completely combined.
Next, divide the cream cheese filling into 2 bowls and set one aside.
In one of the bowls, add 1/2 of the berry jam mix to combine. Save the reserved to top the cheesecake.
Proceed to pour the berry cheesecake into your prepared crust and smooth out into an even layer. Tap the pan against the counter a few times to allow the layer to settle.
Then, add the plain cream cheese filling on top and smooth it out using a rubber spatula.
After that, dollop the reserved berry sauce onto the pie and then swirl it on top using a butter knife. You can try to swirl it in if you want as well, but depending on how thick it is, it may not swirl easily. You can add pockets of the jam into the plain cheesecake as you add it to the pan for better swirling. Do not go too deep with the knife, you only want to swirl the top, not the bottom layers.