01 - Combine warm milk and yeast in a large mixing bowl and allow to stand until foamy, about 5 minutes. Add melted butter, mashed bananas, granulated sugar, egg, and salt; mix to combine. Gradually add the flour, mixing until a shaggy dough forms. Knead for 8–10 minutes until smooth and elastic, either by hand or using a stand mixer fitted with a dough hook.
02 - Transfer the dough to a lightly greased bowl, cover with a towel or plastic wrap, and allow to rise in a warm area for 1 hour or until doubled in size.
03 - In a small bowl, blend together the brown sugar, cinnamon, and nutmeg until evenly mixed.
04 - Punch down the risen dough. On a floured surface, roll the dough into a 16 by 12 inch rectangle. Evenly spread the softened butter over the dough, then sprinkle the cinnamon sugar filling across the surface.
05 - From the long side, tightly roll the dough into a log. Slice into 12 uniform rolls.
06 - Arrange the rolls cut-side up in a greased 9 by 13 inch baking dish. Cover and let rise for 30–45 minutes, until noticeably puffy.
07 - Preheat the oven to 350°F. Bake the rolls for 22 to 25 minutes, until golden brown and set.
08 - While the rolls bake, beat together the cream cheese, softened butter, powdered sugar, milk, and vanilla extract until smooth and creamy.
09 - Cool the rolls for 10 minutes, then generously spread the icing over the warm rolls. Serve immediately.