Preheat your oven to 350°F and prepare two muffin pans with paper liners.
Separate the eggs, whisk the egg whites until stiff peaks form, and set them aside.
In a large mixing bowl, cream the butter until it's light and airy. Add the mashed bananas, egg yolks, and vanilla extract, and mix until the batter is smooth. Gently fold in about a third of the egg whites into this mixture.
In a separate bowl, combine the cake flour, sugar, baking powder, baking soda, salt, and cinnamon. Slowly fold these dry ingredients into the banana mixture until just incorporated. Fold in the remaining egg whites gently.
Scoop the batter into the lined muffin cups, filling each halfway. Bake for 15 minutes, or until a toothpick inserted into the center comes out clean. Allow the cupcakes to cool fully before frosting.
To prepare the frosting, beat the butter and cream cheese together until they are creamy and smooth. Gradually add in the powdered sugar, continuing to beat until the frosting is light and fluffy. Mix in the vanilla extract and cinnamon.
If the frosting is too soft, add more powdered sugar until it's firm enough to pipe but still fluffy. Decorate the cooled cupcakes with frosting, and enjoy!