Preheat the oven to 350 degrees and line an 8x8 baking pan with parchment paper.
Stir the gingersnap crumbs with the melted butter until the mixture resembles wet sand. Press it firmly into the bottom of the prepared pan.
In a mixing bowl, beat the cream cheese until smooth. Add the pumpkin puree, sugar, egg, vanilla, cinnamon, and nutmeg. Mix until fully combined and no streaks remain.
Pour the filling over the crust and spread it evenly.
Bake for 25 to 28 minutes, until the center looks set but still has a slight jiggle.
Cool the pan at room temperature for 30 minutes, then refrigerate until the bars are fully chilled before slicing into four portions.