Preheat and Prep: Preheat the oven to 275 F.
Beat the Cream Cheese: In a large mixing bowl, beat softened cream cheese on medium speed until smooth and creamy (2-3 minutes). Scrape down the bowl as needed.
Add Sugar and Flour: Gradually add granulated sugar and flour, beating until fully incorporated and smooth.
Incorporate Cream and Sour Cream: Add the heavy cream, sour cream, vanilla, lemon juice, and lemon zest. Beat until smooth and creamy.
Add Eggs: Add eggs one at a time, beating on low speed just until combined after each addition (do not overmix to avoid adding air).
Pour into Crust: Pour the cheesecake filling over your prepared graham cracker crust, smoothing the top with a spatula.
Add the Raspberry Syrup: Taking the decorating bottle filled with raspberry syrup, make a ring of small circles starting from the inside of the cheesecake and working your way to the outer edge. It should look like a pinwheel design. Using a toothpick, start from the inner most dot and drag your toothpick through the small circles of raspberry syrup to form hearts. Continue with this until all of the circles are swirled into heart shapes all the way to the outer edge. See photo guide for more details.
Bake: Bake for 1 hour at 275 F, then reduce oven temperature to 250 F and bake an additional 15-20 mins. Center should be slightly jiggly and edges set.
Cool and Chill: Turn off the oven and let the cheesecake cool inside with the door slightly ajar for 1 hour. Remove from the oven, cool completely at room temperature, then refrigerate for at least 6 hours or overnight. I recommend overnight refrigeration for optimal results.