Preheat the oven to 350°F (175°C). Lightly grease a 9-inch (23 cm) pie dish.
Place the graham cracker crumbs, brown sugar, and melted butter in a food processor. Mix until the crumbs are evenly moistened into a smooth dough.
Press the mixture firmly into the bottom and up the sides of the pie dish, forming an even layer. Place the pie pan into the refrigerator to chill while you assemble the filling. Cut the fresh sweet potatoes into large chunks and place them in a saucepan. Cover with water and bring to a boil over medium-high heat. Reduce to medium heat and cook for 10-12 minutes, or until fork tender. Drain thoroughly and transfer to a large mixing bowl.
Place the sweet potatoes into a food processor along with the butter, brown sugar, maple syrup, cream cheese, molasses, vanilla extract, cinnamon, nutmeg, cloves, cardamom, cornstarch, and salt. Mix for 2 minutes until completely smooth.
Pour the filling into the prepared crust, spreading it evenly with an offset spatula. Bake for 45–50 minutes, or until the center is set and the edges appear firm.
Remove from the oven and allow the pie to cool to room temperature, then refrigerate for at least 3 hours before serving.
Serve chilled or at room temperature with vegan whipped cream or ice cream. Garnish with candied pecans and a light dusting of cinnamon if desired.