In a bowl, combine gingersnap and graham cracker crumbs with powdered sugar and butter. Toss to combine. Spread evenly onto bottom of 20 cm springform pan. Bake at 180ºC 5 minutes. Cool. In mixer bowl, beat cream cheese until smooth. Gradually add granulated sugar and beat until light. Add eggs, one at a time, beating until well after each addition. Transfer 1 cup mixture to seperate bowl and blend in pumpkin, cinnamon, ginger, nutmeg and Kahlua. Pour half of pumpkin mixture into prepared crust. Top with half of cream cheese mixture. Repeat layers using remaining pumpkin and cream cheese mixtures. Using table knife, cut through layers with uplifting motion in four to five places to create marbled effect. Place on baking sheet and bake at 180ºC for 45 minutes. Without opening oven door, let cake stand in turned off oven 1 hour. Remove from oven and cool, then chill. Remove from pan.