In a small bowl, combine the walnuts, cracker crumbs, sugar and spices; stir in butter. Press onto the bottom of an ungreased 10-in. tart pan with a removable bottom.
Chill for about 1 hour.
For filling, in a large mixing bowl, beat cream cheese and sugar until smooth. Add eggs; beat on low speed just until combined. Add pumpkin and 1/4 teaspoon cinnamon; beat on low speed just until combined. Pour into crust; sprinkle with walnuts and remaining cinnamon. Place pan on a baking sheet.
Bake at 350 degrees F (190C) for 35-40 minutes or until center is almost set. Cool on a wire rack for 1-1/2 hours. Store in the refrigerator.