For the crust: Combine graham cracker crumbs, chopped pecans (if using), sugar, and salt in a bowl. Pour melted butter over the mixture and stir until evenly moistened. Press firmly into the bottom and up the sides of a 9-inch tart pan with removable bottom. Refrigerate for at least 30 minutes to set (or bake at 350°F for 10 minutes for a crispier crust, then cool completely).
For the filling: In a large bowl, beat softened cream cheese with an electric mixer on medium speed until completely smooth and creamy (about 2-3 minutes). Add pumpkin puree, maple syrup, maple extract, vanilla extract, pumpkin pie spice, cinnamon, nutmeg, ginger, cloves, and salt. Beat on medium-low speed until everything is well combined and smooth, scraping down the sides as needed.
Pour the filling into the prepared crust and smooth the top with a spatula. Tap the pan gently on the counter to release any air bubbles. Cover loosely with plastic wrap and refrigerate for at least 4 hours, but ideally overnight (8-12 hours).
Before serving, make the maple whipped cream: beat cold heavy cream, maple syrup, vanilla extract, maple extract, and salt on medium-high speed until stiff peaks form (3-4 minutes). Spread or pipe the whipped cream over the chilled tart. Top with candied pecans and drizzle with extra maple syrup. To slice, use a sharp knife dipped in hot water and wiped dry between each cut.