2 To Make Crust: In a medium bowl, combine pretzel crumbs, sugar and butter. Press mixture into the bottom and 1 3/4 inches up the side of a 9 inch springform pan.
3 Bake in preheated oven for about 10 minutes, or until firm and lightly browned. Remove from oven and let cool completely.
4 To Make Filling: Allow cream cheese to reach room temperature. In a large bowl, beat cream cheese until smooth. In a separate bowl, combine pudding mix and milk, then mix in with cream cheese. Beat in lime juice, rum extract and lime and lemon zest.
5 Fold 1/2 of the whipped topping into the mixture, then pour into cooled crust. Cover and refrigerate for at least 8 hours. Garnish with remaining whipped topping, lime zest and slices, if desired.