• In a medium-sized saucepan, whisk together the sugar, cornstarch and salt until no lumps remain. Gradually whisk in the cream, then milk. Add yolks and the seeds scraped from the vanilla bean; whisk to blend. Cook over medium-heat, whisking constantly, until the filling thickens and boils, about 5 minutes. Add the butter and stir until melted. Spread the warm filling into the cooled crust. Chill until the filling is cool, about 1 hour.
• Thinly slice 3 bananas on the diagonal. In a medium bowl, combine the banana slices and 2 tablespoons of orange juice; toss to coat. Transfer the banana slices to a paper towel, pat dry. Arrange enough banana slices in a single layer over the filling to cover it completely.

MAKE THE PEANUT BUTTER LAYER:

• In a medium bowl, use an electric mixer to combine the cream cheese and powdered sugar until smooth. Beat in the vanilla and then the peanut butter. In another bowl, use clean, dry beaters to beat the cream until firm peaks form. Fold a large spoonful of whipped cream into the peanut butter mixture to loosen then fold in the remaining cream in 2 additions. Spread the peanut butter layer evenly over the bananas. Chill for at least 3 hours.
• Thinly slice the remaining banana on the diagonal. Toss with the remaining orange juice, then pat dry with paper towels. Arrange the banana slices around the top edge of the pie.