Preheat your oven to 350°F (175°C). In a mixing bowl, combine black cocoa powder, flour, sugar, and melted unsalted butter until the mixture resembles coarse crumbs. Press this blend firmly into the bottom and up the sides of a 9-inch pie plate. Bake for 10-12 minutes, or until set, then allow it to cool completely.

Melt the semi-sweet chocolate in a double boiler or microwave. Brush the melted chocolate over the cooled crust. Let it rest for about 15 minutes until the chocolate sets.

In a medium saucepan over medium heat, whisk together peanut butter, room temperature eggs, sugar, and salt until well combined. Cook while stirring for about 5-7 minutes until the mixture thickens and bubbles lightly. Stir in melted chocolate until fully blended.

Pour the custard into the prepared crust, spreading it evenly. Cover loosely with plastic wrap and refrigerate for at least 4 hours until set.

Before serving, slice fresh bananas and layer them over the top of the custard. Sprinkle pieces of peanut brittle over the bananas.

Slice the pie with a warm, sharp knife. Serve chilled, ideally with a dollop of whipped cream.