Preheat your oven to 325°F (160°C).
In a mixing bowl, combine graham cracker crumbs, melted butter, brown sugar, and cinnamon. Press this mixture into the bottom of a 9-inch springform pan to create an even crust. Bake in the oven for about 10 minutes, then let it cool.
In another bowl, beat the cream cheese with an electric mixer until smooth. Gradually add granulated sugar and continue beating until combined.
Add the mashed sweet potatoes, eggs (one at a time), vanilla extract, nutmeg, and cinnamon to the cream cheese mixture. Beat until smooth and well mixed.
Gently fold in the sour cream and mix until fully incorporated.
Pour the filling over the cooled crust in the springform pan, spreading it evenly.
Place the springform pan into a larger baking pan and fill the outer pan with water until it reaches halfway up the sides of the springform pan.
Bake for about 60 minutes, or until the center is set but slightly jiggly. Turn off the oven and leave the cheesecake inside for another hour.
Remove the cheesecake from the oven and cool at room temperature for 30 minutes. Refrigerate for at least 4 hours or overnight before serving.