Instructions

• Preheat oven to 350°F (175°C). Lightly grease or butter the sides of a 9×13-inch glass baking dish.
• In a medium bowl, whisk together 1 1/2 cups all-purpose flour, 1 1/2 cups whole wheat pastry flour, 1 tablespoon baking powder, 1/2 teaspoon salt, and 1/3 cup cocoa.
• In a large bowl, whisk 2 large eggs and 1 cup sugar until smooth. Add 1 cup milk and 1/2 cup melted coconut oil and whisk until combined.
• Stir 3 mashed ripe bananas and 2 teaspoons vanilla extract into the wet mixture until mixed.
• Gradually add the dry ingredients to the wet mixture and stir until just combined. Fold in 1 cup chocolate chips.
• In a small bowl, blend 4 tablespoons butter with 1/4 cup brown sugar until combined. Spread this butter–sugar mixture evenly in the bottom of the prepared baking dish.
• Arrange the 1 sliced banana in a single layer over the butter–sugar mixture.
• Drop spoonfuls of the 3/4 cup chunky peanut butter over the banana layer, distributing the dollops evenly.
• Spoon the chocolate banana cake batter over the banana and peanut butter layer, filling the dish and smoothing the top as needed.
• Bake for 45–55 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs. Remove from oven and let cool in the pan for 10 minutes.
• Run a knife around the edges to loosen, then invert the cake onto a platter. Let the inverted cake cool slightly while you make the sauce.
• In a microwave-safe bowl combine the remaining 4 tablespoons butter, remaining 1/4 cup brown sugar, 2 tablespoons creamy peanut butter, and 1 teaspoon vanilla extract. Microwave in 30-second intervals, stirring after each, for a total of about 1 minute, until smooth and melted.
• Pour the warm peanut butter caramel sauce over the cake, let it set slightly, then cut into squares and serve.