1. Combine crumbs, butter and sugar in bowl. Pat onto bottom of ungreased 10-inch springform pan with removable bottom. Refrigerate.
2. Heat oven to 350 degrees F.Cake:
3. Beat cheese in bowl at medium speed until smooth. Add sugar, 3 eggs, vanilla; beat until well blended. Pour into prepared pan.
4. Bake in 350 degrees F oven 30 minutes. Cool on rack 15 minutes. Increase oven temperature to 375 degrees F.Topping:
5. Combine brownie mix, water, 3 eggs, oil in bowl. Pour over top of partially baked cheesecake. Sprinkle with nuts.
6. Bake in 375 degrees F oven 45 minutes, covering loosely with foil for last 15 minutes. Cool cake in pan on rack. Refrigerate overnight.