In a small bowl, combine bananas, egg, and melted butter. Whisk to combine. Set aside.
In the bowl of a stand mixer, combine 3 cups flour, yeast, sugar, salt, and baking powder.
Add warm milk to flour mixture. Mix until almost completely incorporated.
Add banana mixture, cornstarch, and remaining 1 ½ cups flour. Mix until combined. Switch to dough hook and beat until dough is smooth and elastic. Cover dough with a kitchen towel and let rise until doubled in size, about one hour.
After the dough has doubled in size, dough out onto a lightly floured surface and knead slightly to form a ball.
For Filling/Assembly:
Roll dough into a 16" x 22" rectangle. Spread butter over the dough with a knife or offset spatula.
In a small bowl, combine all filling ingredients and mix to incorporate. Sprinkle the filling evenly over the dough.
Starting with the long side of the dough, roll the dough tightly. Cut rolled dough into 12 equal pieces and place in a greased 9" x 13" pan. Cover with a kitchen towel and allow to rise until doubled in size, about 45 minutes.
Preheat oven to 350F. Bake 20-25 minutes, or until golden. Remove pan from the oven to cool slightly.
For Frosting:
In the bowl of a stand mixer, combine cream cheese and butter. Beat until smooth. Scrape down the sides of the bowl.
Add caramel sauce (see note) and sifted powdered sugar. Beat until smooth.Spread frosting on warm cinnamon rolls.Enjoy!
Notes
Note on Frosting: This recipe makes a lot of frosting. Enough to where my pan of cinnamon rolls looked more like a cake. :D If that's not how you roll (see what I did there?), you can half the frosting recipe.Note on Salted Caramel Sauce: You can buy salted caramel sauce or make your own!