For the Crust:

1. Line the bottom of a 9-inch (22.8-cm) springform pan with parchment, wrapping around the removable bottom of the pan.
2. Grind the graham crackers into fine crumbs using a food processor or blender.
3. In a microwave-safe bowl, combine graham cracker crumbs with the brown sugar, cinnamon and melted butter. Stir the melted butter into the crumbs until there are no dry crumbs left.
4. Pour the crumbs into your springform pan and press firmly into the bottom and up the sides of the pan to create a thick crust. Refrigerate the crust while you are preparing the filling.

For the White Chocolate Mousse: 

1. Place the mixing bowl and whisk attachment in the freezer for 5 to 10 minutes to chill while you are preparing the next steps.
2. Place 1 tablespoon of cold water in a small dish. Sprinkle the powdered gelatin over the water, spreading evenly. Allow the gelatin to turn to a solid (about 2-3 minutes)
3. In a microwave-safe bowl, microwave the white chocolate at 50% power in 30-second increments, stirring each time until the chocolate is melted and smooth. Set aside.
4. Next, melt the gelatin in the microwave for 5-8 seconds until it turns back to a liquid. Watch it closely!
5. Pour the heavy whipping cream into the chilled bowl and use an electric mixer to beat the heavy cream on medium-high speed until the cream starts to thicken.
6. Slowly add the powdered sugar and liquid gelatin and continue beating on high speed until stiff peaks form. Set the whipped cream aside.
7. Soften the unwrapped cream cheese in the microwave for 15 seconds. Change the mixer to the paddle attachment and beat the cream cheese until it’s completely smooth.
8. Scrape down the sides of the bowl, and add the melted chocolate, beating until it’s completely mixed into the cream cheese.
9. Lastly, fold in the prepared whipped cream and mix until all ingredients are combined. Pour the filling into the prepared crust, spread evenly. Set aside.

For the Pumpkin Mousse:

1. Place mixing bowl in the freezer for 5 minutes to chill. Beat the mascarpone at a low speed, slowly adding heavy cream (scrape down the bowl as needed) until mascarpone resembled a liquid mixture and add all remaining heavy cream.
2. Increase speed to medium-high beating until cream gets bubbly. Slowly add the powdered sugar, brown sugar and pumpkin pie spice and continuing beating until soft peaks form.
3. Slowly add the pumpkin puree and continue beating until stiff peaks form. Pour the filling over the white chocolate layer, spread evenly. Cover and refrigerator 3-4 hours.

For the Topping: 

1. Prepare another batch of whipped cream by placing your bowl in the freezer for 5-10 minutes. To prepare the whipped cream, pour the heavy whipping cream into the chilled bowl and use an electric mixer to beat the heavy cream on medium-high speed until the cream starts to thicken. Slowly add the powdered sugar and continue beating on high speed until stiff peaks form.
2. Pipe the borders of the pie with whipped cream using a large open round tip. Garnish with pecans. Store covered in the refrigerator.