Preheat your oven to 350°F (175°C).
Combine the crushed ginger snap cookies with the melted butter in a bowl until the mixture resembles wet sand.
Press the crumb mixture firmly into the bottom of a 9×13 inch baking dish and toast for 8-10 minutes. Let cool completely.
In a large mixing bowl, beat the softened cream cheese with powdered sugar and vanilla until smooth and creamy.
Spread the cream cheese layer evenly over the cooled ginger snap crust.
In a separate bowl, whisk together the pumpkin puree, instant pudding mix, milk, cinnamon, ginger, and nutmeg until well combined and thickened.
Fold half of the whipped topping into the pumpkin mixture.
Spread the pumpkin mixture over the cream cheese layer.
Top with the remaining whipped topping and garnish with additional ginger snap crumbs if desired.
Refrigerate for at least 4 hours, or preferably overnight, before serving to ensure clean layers.