Preheat oven to 350 degrees. Wrap bottom of springform pan with three sheet of aluminum foil. Set aside.
Crush graham cracker sheets into crumbs by hand or in a food processor or blender.
Combine graham cracker crumbs with melted butter, brown sugar, cinnamon, ginger, and sea salt then press mixture into bottom of prepared springform pan.
Using a hand mixer or a stand mixer, beat cream cheese until smooth (about 4 minutes).
Add in sweet potato puree, eggs, brown sugar, granulated sugar, sour cream, flour, vanilla extract, cinnamon, nutmeg, and sea salt. Mix until uniform and smooth and uniform, pausing to scrape down sides of bowl, as necessary. There may be some small pieces of sweet potato in the batter but no dry pockets of flour should remain.
Gently pour batter into prepared crust. Gently tap the pan on countertop to settle the batter and use a spatula to spread it evenly. Place pan in oven and bake for about one hour. See recipe notes for tips on doneness.
Place the springform pan flat into the middle of a larger pan. Pour one inch of boiling water into the large pan. Place pan onto center rack of oven and bake for about one hour. (See recipe notes for gauging doneness).
Remove cheesecake from oven and allow it to come to room temperature on countertop then cover and transfer to fridge to chill and set for at least four hours.