Preheat the oven to 350°F. Spray at round cake pan with nonstick cooking spray.
In a large bowl, whisk together the flour, granulated sugar, baking powder, baking soda and salt.
Mash one very ripe banana with a fork, making it as mushy as possible without lumps.Add the mashed banana, softened butter, milk, eggs and vanilla extract to the bowl.
Use a hand mixer to combine ingredients together.
Use a spatula to add the batter to the cake pan. Tap the pan on the counter three times to help remove any air bubbles.
Bake for 38-42 minutes or until a toothpick comes out clean when poked in the center (I baked mine for 40 minutes). Let cool 10 minutes.
Gently remove the cake and place on a rack to cool completely.
Make The Frosting:
Add the chocolate to a bowl and microwave for 20 second increments, stirring in between. Once the chocolate is melted add in the peanut butter and stir together.
Now add the whipping cream and mix as much as you can. The chocolate will start to harden because the whipping cream is cold.
Add the mixture back to the microwave for another 20 seconds. Stir together to see if it's reached the desired frosting consistency. If it hasn't, heat for another 20 seconds.
Spread frosting onto the cake with a spatula. Sprinkle the top with chocolate chips. Place in the fridge for 30 minutes to let the frosting chill and harden. Once chilled, you can slice, serve and enjoy!