Heat 2 3/4 cups of the milk in a large saucepan over medium heat until hot but not boiling. Whisk the granulated sugar, cornstarch and salt in a large bowl. Whisk in the egg yolks and the remaining 1/4 cup milk. Whisk half of the hot milk into the egg mixture until smooth, and then gradually whisk the egg mixture into the heated milk. Cook over medium heat, whisking constantly, until the mixture boils and thickens, 4 to 6 minutes. Remove from the heat and whisk in the peanut butter until melted. Transfer to a bowl and cool slightly, about 5 minutes, stirring occasionally to prevent a skin from forming.
Meanwhile, place the pie crusts on a baking sheet or large platter. Place 2 teaspoons of the fruit jelly on the bottom of each pie crust. Smooth out slightly with the back of a spoon or a small offset spatula. Evenly divide the slightly cooled pudding among the pie crusts. Use the back of a spoon or a small offset spatula to spread the pudding to the edges of the pie crusts. Press plastic wrap directly onto the surface of each pie and chill until set, at least 4 hours.
Whip the heavy cream and confectioners' sugar in a large mixing bowl with a hand mixer to medium to stiff peaks. Refrigerate until ready to use.
To assemble, whisk the remaining fruit jelly with 2 teaspoons water until smooth. Place a dollop of whipped cream on top of each pie, using the back of a spoon to create a small well in the center of the whipped cream. Spoon a small amount of jelly into the well and garnish with some roasted peanuts.
Regular or natural peanut butter works here, just makes sure it's emulsified.