Prepare crust: Preheat oven to 175 °C (350 °F). Grease a 23 × 23 cm square pan. Stir cookie crumbs, sugar, and melted butter; press firmly into pan. Bake 8–10 min until golden. Cool completely.

Make pumpkin layer: Whisk together purée, spices, sugar, egg, cream, and vanilla until smooth. Pour over cooled crust and bake 20–25 min until set. Cool thoroughly.

Create cream‑cheese layer: Beat cream cheese, powdered sugar, and vanilla until smooth. In separate bowl, whip heavy cream to soft peaks. Fold whipped cream into cream cheese mixture gently. Spread evenly over pumpkin layer.

Chill & serve: Refrigerate at least 2 hours to set. Serve chilled with whipped topping and a sprinkle of cinnamon.