In a large mixing bowl, beat together the softened cream cheese and granulated sugar until the mixture is light, fluffy, and perfectly smooth, which usually takes about 2 to 3 minutes.
Next, gently fold in the sour cream (or Greek yogurt), whipped topping, and vanilla extract. Continue mixing until all ingredients are beautifully combined and uniform.
Carefully pour this creamy cheesecake filling into your prepared graham cracker crust. Use a spatula to gently spread it evenly, ensuring it reaches all the way to the edges.
Warm the raspberry jam in your microwave for about 15-20 seconds. This will make it thinner and much easier to drizzle.
Spoon small dollops of the warmed jam over the top of the cheesecake filling. Then, use a knife to gently swirl the jam, creating a lovely zig-zag or marbled design.
Place the cheesecake into the refrigerator and chill it for 2 to 3 hours, or until it feels completely firm and set. This is crucial for a perfect slice!
Before serving, if you wish, decorate your cheesecake with a bit more whipped topping, fresh raspberries, or a few mint leaves for a pop of color. Serve chilled and enjoy!