Beat butter at medium speed with an electric mixer until creamy; add sugar, beating well.
Combine flour and salt; add to butter mixture, beating until fine crumbs form. Press into bottom of a lightly greased 13- x 9-inch pan.
Bake at 375° for 10 minutes. Cool on a wire rack.
Beat cream cheese at medium speed until smooth. Add sour cream, peanut butter, and half of caramel topping, beating just until blended. Add eggs, 1 at a time, beating just until blended after each addition. Stir in pecans. Pour over prepared crust.
Spoon dollops of hot fudge topping evenly over cream cheese mixture. Swirl batter gently with a knife to create a marbled effect.
Bake at 325° for 45 minutes or until center is almost set. Cool on a wire rack. Cover and chill 8 hours. Cut into 18 squares. Spoon remaining caramel topping and chocolate syrup onto individual plates; top each with a square of dessert.
Tip: Stir fudge topping in a small bowl before dolloping on cheesecake. This will help soften the mixture to easily swirl into cheesecake batter.