Prep the pan and oven: Heat the oven to 325°F (163°C). Line a 9x13-inch baking pan with parchment, leaving an overhang on the long sides for easy lifting.

Make the crust: In a bowl, mix graham crumbs, sugar, cinnamon, salt, and melted butter until the crumbs look like wet sand. Press firmly into the pan in an even layer. Use the bottom of a measuring cup to compact it.

Par-bake the crust: Bake for 8–10 minutes until fragrant and lightly set. Let it cool while you prepare the filling.

Beat the cream cheese: In a large bowl, beat softened cream cheese on medium speed until smooth and fluffy, about 2 minutes. Scrape down the bowl well.

Add sugar and sour cream: Mix in granulated sugar, sour cream (or yogurt), vanilla, lemon juice, and salt. Beat until smooth, about 1 minute, scraping the bowl as needed.

Add the eggs: Beat in the eggs one at a time on low speed, just until combined. Don’t overmix. Reserve 1 cup of this plain cheesecake batter in a separate bowl.

Make the pumpkin layer: To the large bowl of cheesecake batter, add pumpkin puree, brown sugar, spices, and flour. Mix on low until smooth. The batter will be slightly thicker.

Assemble the layers: Pour the pumpkin batter over the cooled crust and smooth it out. Dollop spoonfuls of the reserved plain cheesecake over the top, then use a butter knife to gently swirl for a marbled look.

Bake: Bake at 325°F for 35–42 minutes. The edges should be set, and the center should have a slight jiggle. Avoid overbaking.

Cool and chill: Cool in the pan on a rack for 1 hour. Then refrigerate for at least 4 hours, or overnight, until fully set.

Slice and serve: Lift the slab out using the parchment. Warm a sharp knife under hot water, wipe dry, and make clean slices. Add whipped cream, caramel, or nuts if you like.