Preheat the Oven

1. Preheat your oven to 350°F (175°C).
2. Grease an 8×8-inch baking pan or line it with parchment paper.

Prepare the Brownie Batter

1. In a large mixing bowl, combine the melted butter and granulated sugar. Stir in the eggs and vanilla extract until well combined.
2. Sift in the cocoa powder, flour, salt, and baking powder. Mix until just combined. Fold in the mashed banana until evenly distributed.

Bake the Brownies

1. Pour the brownie batter into the prepared baking pan, spreading it evenly.
2. Bake for 25–30 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs. Allow the brownies to cool completely in the pan.

Prepare the Banana Pudding Topping

1. In a medium bowl, whisk together the instant vanilla pudding mix and milk until smooth and thickened. Stir in the vanilla extract.
2. Gently fold in the whipped cream until well combined.

Assemble the Brownies

1. Spread the banana pudding mixture evenly over the cooled brownies.
2. Top with crushed vanilla wafers and sliced bananas for decoration.

Chill and Serve

1. Refrigerate the assembled brownies for at least 1 hour to allow the pudding to set.
2. Cut into squares and serve chilled.