1In a small bowl, stir together crushed wafers and sugar. Add melted butter or margarine. Stir till well combined. Press crumb mixture evenly onto the bottom and up the sides 1/2 way of a greased 9 inch springform pan. Set aside
2In a large bowl, combine cream cheese, sugar, cornstarch. Beat with electric mixer till smooth.
Add eggs and egg yolk, one at a time, beating well after each addition. Beat in pureed banana, banana schnapps, and vanilla extract. Pour the cream cheese mixture over the crust.
3Bake at 350 for 15 minutes. LOWER the temperature to 225 and bake for 1 hour and 10 minutes or till the center no longer looks wet or shiny. Remove the cake from the oven and run a knife around the inside edge of the pan. (This helps prevent cracking of the cheesecake.) Turn the oven off; return the cake to the oven for an additional 30 minutes. Chill uncovered, overnight.
4Just before serving, garnish with fruit. Drizzle with warm ice cream topping.
If desired, add nuts and dollops of whipped cream.