Prep the pan: Line a 9x13-inch baking pan with parchment, leaving overhang on the long sides for easy lifting. Lightly grease the sides.
Heat the oven: Preheat to 325°F (163°C).
This gentler heat helps prevent cracking and overbrowning.
Make the crust: In a bowl, mix graham crumbs, sugar, salt, and melted butter until the texture resembles wet sand. Press firmly and evenly into the lined pan using the bottom of a measuring cup.
Par-bake the crust: Bake for 8–10 minutes until lightly fragrant. Cool for 5 minutes while you make the filling.
Beat the cream cheese: In a large bowl, beat the cream cheese on medium speed until smooth and creamy, about 2 minutes.
Scrape the bowl well.
Add sugar and sour cream: Beat in sugar, then sour cream, vanilla, lemon zest/juice, and salt until just combined and silky. Avoid overbeating.
Add the eggs: Beat in eggs one at a time on low speed until blended. Stop as soon as they disappear into the mixture.
Overmixing whips in air and can cause cracks.
Fill the pan: Pour the batter over the crust. Smooth the top with an offset spatula to even out the layer.
Bake gently: Bake at 325°F for 28–35 minutes. The edges should be set, and the center should jiggle slightly like gelatin, not slosh.
Cool gradually: Turn off the oven, crack the door, and let the pan sit for 10 minutes.
Then transfer to a rack to cool for 1 hour.
Add the top layer: Sour cream topping: Stir sour cream, sugar, and vanilla. Spread over the cooled (but still slightly warm) cheesecake. Return to the oven for 5 minutes to set, then cool again.
Ganache: Warm cream until steaming.
Pour over chocolate chips and let sit 2 minutes. Stir until smooth, then spread over fully cooled cheesecake.
Chill: Cover and refrigerate at least 4 hours, preferably overnight. This sets the layers and deepens the flavor.
Slice and serve: Lift out using the parchment overhang.
Warm a sharp knife under hot water, wipe it dry, and slice into bars. Wipe between cuts for clean edges.