Preheat oven to 325°F (170°C). Spray an 8 1⁄2×4 1⁄2-inch loaf pan with baking spray with flour. Line pan with parchment paper, letting extra prolong over all sides of pan.
For batter: In a medium bowl, whisk collectively flour, salt, baking powder, and baking soda.
In a big bowl, whisk collectively banana, brown sugar, peanut butter, bitter cream, oil, eggs, and vanilla. Step by step stir in flour combination simply till mixed. Unfold batter into ready pan.
Bake for 50 minutes. Rotate pan, and bake till a wood choose inserted in middle comes out clear and an instant- learn thermometer inserted in middle registers 200°F (93°C) to 205°F (96°C), 35 to 45 minutes extra, loosely protecting with foil throughout remaining 20 minutes of baking to forestall extra browning. Let cool in pan on a wire rack for 10 minutes. Utilizing extra parchment as handles, take away from pan, and let cool utterly on wire rack. Wrap cooled loaf in plastic wrap, and refrigerate for 1 hour.
Unwrap loaf, and place on wire rack on a rimmed baking sheet.
For topping: In a medium microwave- secure bowl, warmth all elements on excessive in 30-second intervals, stirring between every, till chocolate and butter are melted and combination is properly mixed. Pour topping throughout prime and sides of loaf, spreading with an offset spatula to cowl. Refrigerate till set, about 10 minutes, earlier than serving. Retailer in hermetic container for as much as 3 days.
