Preheat oven to 375°F (convection not recommended).
PREPARE POTATOES AND CRUST:
Peel the sweet potatoes and cut in half lengthwise. Place in a 9x13-inch baking pan and brush with melted butter. Bake until the potatoes are soft when pressed, 45 to 55 minutes.
Meanwhile, prepare the crust: Whirl pecans in a blender until finely ground; you should have ¼ cup. In a bowl, mix the pecans, graham cracker crumbs, sugar and butter. Pour into 9-inch springform pan with removable rim (2¼-inches tall). Press the mixture evenly over the bottom of the pan. Bake in the same oven with the potatoes until lightly browned all over, 10 to 12 minutes.
Scrape any charred spots off the potatoes, then cut the potatoes into chunks. Whirl in a food processor or mash in a bowl with lemon juice until smooth. Reserve 1 cup; save any extra for another use.
Reduce the oven temperature to 325°F.
PREPARE THE FILLING:
In a bowl, with a mixer on high speed, beat the cream cheese until fluffy. Gradually beat in the granulated and brown sugars, scraping down the sides of the bowl occasionally, until the mixture is well blended and smooth. Beat in the eggs, one at a time, until blended. Add the reserved sweet potato mixture, the whipping cream, sour cream, maple syrup, cinnamon, nutmeg, and ginger. Mix on low speed until well blended.
Wrap the bottom of the springform pan with a double layer of heavy-duty foil, pressing it up the sides. Pour the batter over the crust. Put the pan in a 12x15-inch roasting pan at least 2 inches deep. Set the pans in the oven and pour enough boiling water into the roasting pan to come halfway up the sides of the springform pan.
Bake until the cake barely jiggles in the center when gently shaken, about 55 minutes. Remove the pans from the oven. Lift the springform pan from the roasting pan and let it cool completely on a rack, about 1 hour, then chill until cold, at least 1½ hours, or up to 3 days (cover once cold).
Up to 6 hours before serving, cut around inside of the pan rim to release the cheesecake; remove the rim.
PREPARE THE MAPLE WHIPPED CREAM:
In a bowl, with a mixer on high speed, beat the whipping cream until stiff peaks form. On low speed, beat in the maple syrup just until blended. Spoon the maple whipped cream onto each individual serving.
Notes
*You can make this cheesecake up to 3 days ahead; cover and chill. Garnish with whipped cream up to 6 hours before serving; cover and chill until serving.