Peanut butter lovers, rejoice. This pie is so good, and it has a twist: Melba toast replaces graham cracker crumbs for a crisp, salty foil to the decadent filling.
Preheat oven to 350°. In a medium bowl, combine crushed toasts, butter, 2 tablespoons of the sugar and 1/4 teaspoon of the sea salt. Stir to evenly coat. Press mixture onto bottom and sides of a 9-inch pie plate. Bake crust until lightly golden, about 8 minutes. Cool completely on a wire rack.
In a small bowl, whisk together the water and gelatin. Let stand 10 minutes.
Meanwhile, in a medium, heavy-bottom saucepan, whisk together egg yolks, the remaining 1 cup sugar, the milk and 1/4 teaspoon of the sea salt. Cook, stirring constantly, over medium heat until custard thickens and begins to bubble. Remove from heat; add gelatin mixture. Whisk until gelatin has dissolved and mixture is smooth. Whisk in peanut butter, vanilla and the remaining 1/8 teaspoon sea salt. Cool to room temperature.
In a large bowl, beat 1 cup of the cream with an electric mixer on medium-high speed until stiff peaks form (tips stand straight). Fold about one-third of the whipped cream into the peanut butter custard. Gently fold in the remaining whipped cream until just a few streaks of white remain. Gently spoon filling into cooled pie crust. Chill at least 3 hours or up to overnight.
To finish: In a large bowl, beat the remaining 3/4 cup cream with an electric mixer on medium-high speed until soft peaks form. Spoon whipped cream over filling, then top with peanuts.