Blend cream cheese and sugar in processor until smooth. Add pumpkin, eggs, vanilla and spices. Process until smooth, scraping down sides of bowl. Transfer filling to crust. Bake cheesecake until center is set and edges begin to crack, about 1 hour and 5 minutes. Cool in pan on rack. Chill uncovered until cold, at least 6 hours. This can be made 1 day ahead. Cover; keep chilled.
Cut around pan sides; remove sides. Arrange pecans decoratively on cake.