If you are using the sweetened condensed milk to make dulce de leche, you will want to do this several hours before making the pie. Place the unopened can in a large saucepan or dutch oven and cover with water by about 2 inches. Bring to a boil, When the water is boiling, turn heat to medium low and mostly cover with lid allowing some venting. Adjust temperature as needed to keep it at a low boil.Allow to simmer for 3 hours. If the water runs low pour in boiling water to continue cooking, keeping the can submerged. Remove can and allow to cool before opening. Preheat oven to 350°.
Mix together graham cracker crumbs, sugars and butter.
Press the mixture into the bottom of the pie plate or springform pan and about 1½ inches up the sides. Use the bottom of a measuring cup to press the crust firmly.
Bake for 15-16 minutes
Remove and cool for at least 15 minutes.
Drizzle the dulce de leche onto bottom of pan, gently spread with spoon being careful to not pull up crust. **Keep a couple of tablespoons out for the topping.
Slice bananas and spread over dulce de leche.
Whip the cold whipping cream, sugar, cream cheese and vanilla on medium-high speed until medium to stiff peaks form, about 4-5 minutes. *Do not over whip. Stop when good peaks form.
Spread whipped cream over bananas.
Chop up chocolate bar into small chunks and sprinkle over whipped cream.
Refrigerate, uncovered, for at least 2 hours. (3 is better!)