Combine crumbs, pecans and margarine; press onto bottom and 4 cm up sides of 23 cm springform pan. Bake at 180ºC ., 10 minutes. Combine cream cheese, half c sugar and vanilla, mixing at medium speed on electric mixer until well blended. Add eggs, one at a time, mixing well after each addition. Reserve 1 c batter, chill. Add remaining sugar, pumpkin and spices to remaining batter; mix well. Alternately layer pumpkin and cream cheese batters over crust. Cut through batters with knife several times for marble effect. Bake at 180ºC ., 55 minutes. Loosen cake from rim of pan; cool before removing rim of pan. Chill.