In a medium bowl, stir together crushed vanilla wafers, chopped pecans, and melted butter. Press into bottom of a greased 9-inch springform pan.
Stand 17 vanilla wafers around edge of pan with rounded sides facing outward. Press them gently into the crust.
In a small saucepan, combine bananas (both diced and mashed) and lemon juice. Stir in brown sugar, using 2 tablespoons if your bananas are super ripe and 3 tablespoons if they are medium ripe. Cook over medium heat until brown sugar dissolves, about 1 minute. Remove from heat.
Using an electric mixer, beat cream cheese at medium speed until smooth, about 3 minutes.
Gradually add granulated sugar.
Add eggs, one at a time and stopping to scrape down sides of bowl after each addition. Do not over beat. Only beat until most of yellow disappears before adding next egg.
Beat in vanilla extract.
Stir banana mixture in until evenly mixed. Pour batter into springform pan on top of crust.
Bake for 45 to 55 minutes, until center is almost set. Jiggle the pan to check.
Turn oven off, open door about 6 inches and leave cheesecake in oven to cool for about 1 hour.
Remove cheesecake to counter to cool for another 30 minutes. Cover with plastic wrap and refrigerate for 8 hours before serving.
Garnish with whipped cream and vanilla wafers.
If you're a huge fan of vanilla wafers, try adding 1/2 cup coarsely chopped vanailla wafers to the batter.You can leave the pecans out of the crust if you wish. Add maybe 1/4 cup more vanilla wafer crumbs.