Prepare dulce de leche. This could and probably should be a post by itself. I like making it in slow cooker the best (mine takes a little longer since I'm at high altitude), but this oven method works if you are in a hurry. If you don't want to mess around with making your own, you could always purchase it or just use my favorite Mrs. Richardson's Butterscotch Caramel - it's too die for and seems to be a staple around my house.
Using food processor, pulse oreos into crumbs. If you don't have a food processor, place cookies into a gallon sized zip-loc and smash or roll with a rolling pin until you have crumbs. Melt butter. Pour over crumbs and stir into until they are well coated. Spread in a deep 9x13 baking dish.
Combine pudding mix, water, and sweet condensed mix in a good sized bowl. Stir until smooth. Place in refrigerator while you whip 1 cup of whipping cream until soft peaks form. Gently fold into pudding mixture. Set aside.
Gently spread dulce de leche or caramel over cookie crust. Slice bananas and spread evenly to cover dulce de leche/caramel. Gently spread pudding mixture over the bananas, smoothing to cover evenly.
Whip 1 cup whipping cream, 1/3 cup sugar, and 1/2 to 1 teaspoon vanilla (depending on your taste preference) until soft peaks form. Spread it over the pudding mixture. Sprinkle with toffee bits. Place in refrigerator for a good 4 hours before serving. This is important for the flavor of the pie, even if it is set, it's worth waiting so the banana flavor has time to mingle with the other flavors. Enjoy!