Preheat oven to 350°
Combine gingersnaps with pecans and butter
Press mixture into bottom of a 9" springform pan
Combine cream cheese and sugar, beat with mixer until just combined
Add eggs, spices and rum flavoring
Beat on low speed until just combined, then pour into prepared pan
Bake at 350° for 1 to 1 ½ hour or until center is nearly set when shaken
Cool, then loosen edge of cheesecake from pan with spatula or knife
Remove sides of pan when cake is cooled
Cover and chill for at least four hours
Garnish with pecans