Heat oven to 300°F.
In a medium size bowl, combine the graham cracker crumbs with the melted butter with a fork. Stir and mix well.
With your fingers or the back of a spoon press the crust on the bottom of the prepared pan. Set aside.
In the mixing bowl of your stand-up mixer, add softened cream cheese and sugar. With the paddle attachment on, beat on low speed until light and fluffy.
Beat in eggs, one at a time, just until blended. Do not overmix.
Add in vanilla extract and mix carefully.
Spoon half of the mixture over the crust and spread evenly.
To the remaining cream cheese mixture add the pumpkin puree and pumpkin pie spice.
With a wire whisk stir until smooth. Carefully, spoon over mixture in pan.
Bake the cheesecake in the preheated oven for 50 minutes or until just set. Turn off the oven and leave the door ajar allowing the cheesecake to slowly cool down for about 1 hour or so.
Refrigerate for at least 3 hours before cutting into bars.
Top each bar with whipped cream and a dust of pumpkin pie spice.