Preheat the oven to 350 degrees and line an 8x8 inch pan with parchment paper. Mix the gingersnap cookie crumbs with the melted butter until evenly coated. Press the mixture firmly into the bottom of the pan to form the crust.

In a mixing bowl, beat the cream cheese until smooth. Add the pumpkin puree, sugar, egg, vanilla extract, cinnamon, and nutmeg. Beat again until the filling is fully combined and free of lumps.

Pour the filling over the prepared crust and spread it evenly with a spatula. Bake for 30 minutes until the center is set and no longer jiggles.

Remove the pan from the oven and let the bars cool to room temperature. Chill in the refrigerator for at least two hours before cutting into four squares. Top each bar with a dollop of whipped cream before serving.