Combine pretzel crumbs, 1/2 cup sugar and butter; press onto bottom and 2 inches up side of 9-inch springform pan.
Reserve 2 tablespoons of the remaining sugar. Beat remaining sugar with cream cheese in large bowl with mixer until blended. Add liqueur; mix well. Add eggs, 1 at a time, mixing on low speed after each just until blended; pour into crust.
Bake 1 hour to 1 hour 5 minutes or until centre is almost set. Run knife around rim of pan to loosen cake; cool before removing rim. Refrigerate cheesecake 4 hours.
Spoon caramel sauce over cheesecake, spreading to within 2 inches of edge. Bring 1/4 cup whipping cream to boil in small saucepan. Remove from heat. Add chocolate chips; stir until melted. Let stand 10 minutes or until slightly thickened. Pour over cheesecake; spread to completely cover top.
Beat remaining cream in medium bowl with mixer on high speed until soft peaks form. Add reserved sugar; beat until stiff peaks form. Spoon into pastry bag fitted with star tip; use to pipe whipped cream onto cheesecake just before serving.
To make candied pretzels, cook 2 Tbsp. each brown sugar and dark corn syrup, and 1 Tbsp. butter in medium skillet on medium heat until butter is melted and mixture is heated through, stirring frequently. Add 2 cups small pretzel twists; cook and stir 5 to 7 min. or until sugar syrup darkens in colour and begins to bubble. Spread pretzels onto parchment-covered baking sheet. Melt 1/4 cup chocolate chips as directed on package; drizzle over pretzels. Let stand until chocolate is firm.
If you don't have a pastry bag, you can use a resealable plastic bag instead. Spoon whipped cream into plastic bag. Cut small piece off one bottom corner of bag; use to pipe whipped cream onto cheesecake as directed.
Prepare as directed, omitting the liqueur.
Per Serving: 632 calories;44.7 g fat;
53.7 g carbohydrates;
9.4 g protein;
173 mg cholesterol;
490 mg sodium.