Heat the oven to 350° Fahrenheit and grease two 8-inch round pans with butter or cooking spray. In a large bowl, use an electric mixer to cream together the butter and sugar until fluffy and lighter in color, then set aside. In a small bowl, mash 3.5 bananas together, then add to the butter and sugar mixture and blend. Add in the eggs, sour cream, and vanilla – mix with the electric mixer until well blended.

In a medium bowl, whisk together the flour, baking powder, and salt, then add into the wet ingredients and mix until just blended.

Pour batter into the greased pans. You can slice the remaining 3.5 bananas and lay slices carefully on top of the cake or you can leave the tops of the cakes plain and save the bananas to decorate the frosted cake - or do both! Bake for 40-50 minutes or until a knife inserted into the middle of the cake comes out clean. Let cool completely before flipping the cakes out of the pans and assembling.

While the cakes are cooling, take your now-room-temperature cream cheese and butter and blend them together using an electric mixer. The mixture should be light and fluffy, give it a couple of minutes. Add in the cocoa and blend, then add in the sugar 1/2 cup at a time and taste in between (you can cut the sugar if you like it less sweet). Add in the salt and vanilla extract and blend. If the frosting is too stiff, you can add a tbsp of milk or cream. This frosting is totally up to your taste - I like mine not too sweet but others might light the fluffy, extra-sweet version. As with anything, add a bit of sugar and cocoa powder to start, taste as you go, and keep adding until you're satisfied with the result.

You can frost the entire cake, or just pile heaps of frosting in between the layers and on the top and adorn with extra bananas. If you want an extra bit of chocolate, you can add chocolate shavings or chocolate chips on top for a bit of extra pizazz.