Preheat oven to 350°. Stir together first finely crushed vanilla wafers, pecans, and melted butter in a small bowl until well blended. Grease and flour a 9-inch springform pan and press mixture onto bottom of pan. Line the edge of the pan with vanilla wafers (about 17) with rounded sides against the pan to form a crust. Bake 10 minutes. Cool completely on a wire rack (about 30 minutes).

Combine lemon juice and bananas in a small saucepan. Stir in brown sugar. Cook over medium-high heat, stirring constantly, 1 minute or until sugar has dissolved.

Using an electric mixer, beat cream cheese at medium speed for 3 minutes or until smooth. Gradually add granulated sugar, beating until blended. Add eggs, one at a time. Beat until yellow disappears after each addition. Beat in vanilla, and gently stir banana mixture into cream cheese mixture. Pour batter into crust.

Bake at 350° for 45 minutes or until center is almost set. Remove cheesecake from oven; gently run a knife around edge of cheesecake to loosen. Sprinkle top of cheesecake with coarsely crushed wafers. Cool completely on a wire rack (about 1 hour). 

Cover and chill for 8 hours. Garnish with whipped cream, wafers, and sliced bananas before serving.