Preheat oven to 350 degrees F. Prepare a 9x9x2” square baking pan by lining with parchment paper or buttering generously.
In a large bowl, stir together graham cracker crumbs and melted butter; stir until evenly moistened. Press firmly and evenly into baking pan. Bake for 12 minutes. Keep oven temperature at 350 degrees.
To make cheesecake:
In the large bowl of a standing mixer, beat together cream cheese and sour cream. Add 1/2 cup sugar and beat until light and fluffy. Beat in eggs, one at a time, then vanilla. Remove 1 cup of cheesecake batter and set aside.
To remaining batter, add pumpkin puree, remaining 3 tablespoons of sugar, and spices; beat to combine.
Drop spoonfuls of cheesecake batter onto the prepared crust, alternating between the plain and pumpkin batters. Gently swirl with a knife to create a marbled effect. Bake in centre of preheated oven for 20-25 minutes, or until set (edges will be puff a bit and centre will jiggle only slightly).
Cool on a wire rack to room temperature before cutting into 12 slices. Refrigerate leftovers for up to 3 days.
Video
Notes
A Few Notes:
Make sure to use 100% pure pumpkin. Avoid pumpkin pie filling.
If you don’t have pumpkin pie spice, don’t sweat it. Just use 1 1/2 tsp of cinnamon, 1/4 tsp of ground ginger, 1/4 tsp of nutmeg, and a pinch of cloves.
If using whole graham crackers, that's 28 square graham crackers or 14 double graham crackers. Crush them in a food processor or by hand using a rolling pin.
Use a sharp knife to slice up the bars, and give it a wipe with a warm, wet cloth between cuts to keep the slices perfect.