In a large sauce pot over medium heat, reduce the sweetened condensed milk until it has significantly thickened, stirring to prevent it from burning, for about 45 minutes over medium heat, until it turns a golden brown, becoming toffee. Set aside.
Preheat oven to 350F.
4 cups Chocolate Graham Crackers (ground) 2 sticks Butter (softened)
In a bowl, combine the chocolate graham cracker crumbs and the butter, and mix together. Press into your pie dish to make a crust. Bake for 5 to 8 minutes to set the crust.
9 Bananas (sliced into 1/4-inch thick coins)
Once the crust has cooled slightly, begin to layer with a layer of the toffee. Arrange a fairly solid layer of banana coins over the toffee, and then add another layer of the toffee. Repeat until the pie has been filled, finishing with a top layer of banana coins.
2 cups Mascarpone 2 cups Heavy Cream
Combine the mascarpone and heavy cream in the bowl of a stand mixer. Beat the mixture until whipped and peaks hold.
Dark Chocolate (to shave as garnish)
Top the pie with the mascarpone whipped cream. Garnish the pie with dark chocolate shavings to serve.