Butter cookie crumb crust:
1 1/2 cups finely ground butter cookies (about 30)
6 tablespoons unsalted butter, melted

Banana filling:
7 ripe bananas, divided
3/4 cup whole milk
8 ounces white chocolate, coarsely chopped
2 tablespoons dark rum
1 teaspoon unflavored powdered gelatin
3 cups heavy cream

Make the cookie crumb crust:

Position a rack in the center of the oven and preheat to 350 degrees(F). Butter the bottom of a 9-inch springform pan.
In a small bowl, combine the ground butter cookies and melted butter. Press evenly into the bottom of the prepared pan. Bake for 8 to 10 minutes or until lightly browned; set aside to cool.

Make the banana filling:

Cut 5 of the bananas into 1-inch pieces and combine with the milk in a medium saucepan. Bring to a boil over medium-high heat. Reduce the heat to low and simmer for 5 minutes.
In a food processor fitted with a metal blade, puree the banana mixture until smooth. Pour into a medium bowl and stir the white chocolate into the mixture until completely melted; set aside to cool.
Place the dark rum in a small microwave-safe bowl. Sprinkle the gelatin over and let stand for 5 minutes to soften.
Microwave the gelatin mixture on HIGH for 7 seconds until melted. Let stand 2 minutes. Stir 1/2 cup of the banana purse into the gelatin. Fold the banana gelatin mixture into the remainder of the banana puree and set aside.
In the 4 1/2-quart bowl of a heavy-duty electric mixer fitted with the wire whip attachment, whip the cream until stiff peaks start to form. Stir 1/4 of the whipped cream into the banana filling to lighten it and then fold in the remaining whipped cream in three additions. The filling may have a slightly grainy appearance. Cut the remaining bananas into 1/4-inch pieces. Place the banana slices evenly over the bottom of the crust. Spoon the filling into the cooled crust and refrigerate for 5 hours or overnight until set.

Finish the pie: Run an offset spatula around the outer edge of the pie to loosen. Remove springform ring and garnish pie with whipped cream and fresh banana slices.