Preheat your oven to 350°F (175°C). Crush gingersnap cookies into fine crumbs, mixing with melted butter and a touch of brown sugar until combined. Firmly press into a greased 9-inch springform pan. Bake for 12-15 minutes until golden, then cool.

In a stand mixer, beat the cream cheese until smooth. Gradually add sour cream and sugar until well incorporated. Fold in pumpkin puree, then add eggs, vanilla extract, and pumpkin pie spice until combined.

Lower oven temperature to 325°F (160°C). Pour cheesecake filling into cooled crust. Place the springform pan in a roasting pan, adding boiling water halfway up the sides. Bake for 1 hour and 45 minutes, checking edges set while center is jiggy.

Turn off the oven and leave cheesecake inside for an hour to cool gradually. Remove pan from water bath and cover. Refrigerate for 8-12 hours.

Run a knife around the edges to loosen. Release the springform and slice. Top with whipped cream and nutmeg before serving.