In a mixing bowl, combine graham cracker crumbs and sugar. Pour in melted butter and stir until the mixture resembles wet sand. Press this mixture firmly into the bottom of a parchment-lined 9x13 inch baking pan to form an even crust.
Bake the crust in a preheated oven at 350°F (175°C) for 8-10 minutes until lightly golden. Remove and let it cool slightly as you prepare the filling.
In a large bowl, beat softened cream cheese with a hand mixer or whisk until smooth and creamy, eliminating any lumps. Add sugar and spices, and continue mixing until well combined.
Mix in pumpkin puree, eggs, and vanilla extract, one at a time, mixing well after each addition. The filling should be smooth and slightly fluffy, with a rich, orange hue.
Pour the pumpkin cheesecake filling over the cooled crust, spreading it evenly with a spatula. Tap the pan gently on the counter to remove air bubbles and level the surface.
Bake in the oven at 350°F (175°C) for 30-35 minutes, or until the edges are set but the center still slightly jiggles when gently shaken.
Remove from the oven and let the bars cool completely on a wire rack. Once cooled, refrigerate for at least 2 hours or overnight to fully set.
Cut into squares with a sharp knife, wiping the blade clean between cuts for neat edges. Serve chilled for the best texture and flavor.
