Preheat the oven to 325°F. Grease a 9-inch springform pan.

In a medium bowl, combine graham cracker crumbs, melted butter, granulated sugar, and cinnamon. Mix until well combined. Press the mixture firmly into the bottom of the prepared springform pan to form the crust.

In a large mixing bowl, beat the softened cream cheese with an electric mixer until smooth. Gradually add the granulated sugar and vanilla extract, mixing until well combined. Add the eggs one at a time, mixing well after each addition.

Fold in the grated carrots, crushed pineapple, walnuts (if using), nutmeg, and salt until evenly distributed. Pour the cream cheese mixture over the prepared crust in the springform pan.

In a separate bowl, whisk together the sour cream and brown sugar until smooth. Spread this mixture evenly over the top of the cheesecake.

Bake in the preheated oven for 55-60 minutes, or until the center is set but still slightly jiggly. Turn off the oven and leave the cheesecake inside for an additional hour to cool gradually.

Remove the cheesecake from the oven and let it cool to room temperature. Once cooled, refrigerate for at least 4 hours or overnight before serving.