Preheat oven to 325°F. Line baking sheet with foil. Stir sugar and butter in heavy medium saucepan over medium heat until sugar melts and mixture comes to boil; boil 1 minute without stirring. Mix in pecans. Spread mixture on prepared baking sheet. Bake until sugar syrup bubbles vigorously, about 8 minutes. Cool praline completely. Break into pieces. (Can be made 1 day ahead. Store airtight.)
Preheat oven to 325°F. Stir cookie crumbs and cinnamon in medium bowl to blend. Add butter; stir until crumbs are moistened (may need extra butter). Press onto bottom and 1 inch up sides of 9-inch-diameter springform pan with 2 3/4-inch-high sides. Bake crust until set, about 10 minutes. Cool. Double-wrap outside of pan with heavy-duty foil. Place in large roasting pan.
Pre-heat oven to 350 degrees.
Using electric mixer, beat cream cheese and sugar in large bowl until smooth. Beat in flour and spices. Beat in eggs 1 at a time. Beat in pumpkin, and vanilla. Transfer to crust.
Pour enough hot water into roasting pan to reach 1/2 inch up sides of springform pan. Bake cake in water bath until center is just set, adding more water to roasting pan as needed, about 1 hour 45 minutes. Remove cheesecake from water. Cool in pan on rack. Remove foil. Run small sharp knife between cake and pan sides. Chill until cold; then cover and chill overnight.
Release pan sides. Place cake on platter. Sprinkle praline over, leaving 1-inch plain border at edge. Cut cake into wedges and serve with whipped cream.