Preheat oven at 325 degrees.
Combine wafer crumbs, pecans, sugar, and butter. Press mixture onto bottom of 2 inch by 9 inch springform pan. Chill.
In an electric mixer, beat cheese and sugar until smooth. Beat in eggs one at the time, until just blended. Beat in liqueur and white chocolate. Pour into pan. Bake 50 min. or until center is just set. Remove from oven and run knife around sides of pan to prevent cracking. Cool.
Top cheesecake with whipped cream and chocolate shavings if desired.