Preheat the oven to 325°F degrees and spray a 9×13-inch baking dish with nonstick cooking spray. Set aside.
CRUST
In a medium bowl, add graham crackers, sugar, and pumpkin spice. Mix together.
Add melted butter and mix until all ingredients are fully incorporated (no dry spots).
Press the crumbs firmly into the bottom of the prepared baking dish.
Chill the crust in the refrigerator while you prepare the filling.
FILLING
In a large bowl, add cream cheese and sugar. Using a handheld mixer, mix on low until creamy.
With the mixer on low, add eggs, one at a time, until combined, scraping down the sides of the bowl as needed.
Pour half of the cream cheese mixture onto the crust. Use a spatula to smooth it into an even layer. Set in the freezer to chill for 10 minutes.
To the remaining cream cheese mixture, add the pumpkin puree and pumpkin spice. Mix on low to combine.
Carefully spoon the pumpkin mixture over the cream cheese mixture, smoothing into an even layer.
Bake 50-60 minutes or until cheesecake is slightly set around the edges and jiggly in the center.
Bring the bars to room temperature. Then, chill them in the refrigerator for 4 hours, up to overnight, before adding the topping.
TOPPING
Add heavy cream to a mixing bowl. Start mixing at the lowest speed, and then gradually increase speed to medium until the cream starts to get thicker. (The gradual progression prevents you from spraying yourself with cream.)
When the cream starts to thicken, stop the mixer. Slowly add in the confectioners’ sugar and then resume mixing again, starting with low speed and increasing to medium speed, and eventually moving to a high speed.
The cream will thicken and start to peak. Mix on high until the cream is thick and stiff. This happens quickly, the stage between soft and stiff peaks, so watch it closely.
Spread the homemade whipped topping evenly over the chilled cheesecake bars.
