Heat oven to 325°F. In large bowl, combine cake mix and butter; beat at low speed until crumbly. Reserve 1 cup of crumb mixture for topping. With floured fingers, press remaining mixture in bottom and 1/2 inch up sides of ungreased 10 or 9-inch springform pan.
In same large bowl, combine cream cheese, sugar, flour and rum extract; beat until smooth. Add eggs; mix well. Stir in crushed candy bars. Pour into crust-lined pan.
In medium bowl, combine reserved crumb mixture, brown sugar and pecans; mix well. Sprinkle evenly over filling.
Bake at 325°F. for 70 to 85 minutes or until center is set and topping is golden brown.
Remove cheesecake from oven. Drizzle caramel topping over top.
Return to oven; bake an additional 8 to 10 minutes or until topping is set. Cool 30 minutes. Run knife around sides of pan to loosen. Cool 1 hour or until completely cooled. Remove sides of pan. Refrigerate at least 4 hours or overnight before serving. Store in refrigerator.