For the crust: Mix crumbs, pecans, butter and sugar. Press onto bottom of 13 x 9 inch baking pan.
For the filling: Mix cream cheese, sugar and rum extract with electric mixer on medium speed until well blended. Add eggs; mix until blended. Stir in mashed banana. Pour over crust. Bake at 350° for 30 minutes or until center is almost set. Cool. Refrigerate 3 hours or overnight.
For the topping: Toss bananas with lemon juice; arrange over cheesecake. Microwave caramels and milk in microwaveable bowl on High 2 minutes; stir until smooth (add a teaspoon or so more if too thick). Drizzle evenly over cheesecake. Sprinkle with pecan halves. Cut into squares. Refrigerate any leftover cheesecake.