01 - Combine warm milk and yeast in a large mixing bowl. Allow to stand for 5 minutes until the mixture is foamy. Add melted butter, mashed bananas, granulated sugar, egg, and salt, then stir to combine. Gradually mix in the flour until a shaggy dough forms. Knead by hand or with a stand mixer fitted with a dough hook for 8 to 10 minutes until the dough becomes smooth and elastic.
02 - Transfer the dough to a lightly greased bowl, cover with a clean towel or plastic wrap, and let rest in a warm place for 1 hour or until doubled in volume.
03 - In a small bowl, blend together brown sugar, ground cinnamon, and ground nutmeg.
04 - Gently deflate the risen dough. On a lightly floured surface, roll the dough into a 16 by 12 inch rectangle. Spread softened butter evenly across the surface, then distribute the cinnamon sugar filling evenly over the top.
05 - Starting from the long edge, roll the dough tightly into a log. Slice the log evenly into 12 rolls.
06 - Arrange the rolls with cut sides up in a greased 9 by 13 inch baking dish. Cover and let rise for 30 to 45 minutes, or until puffy.
07 - Preheat the oven to 350°F. Bake the rolls for 22 to 25 minutes, or until golden brown.
08 - While the rolls bake, beat together cream cheese, softened butter, powdered sugar, milk, and vanilla extract until smooth and creamy.
09 - Let the baked rolls cool for 10 minutes, then generously spread the cream cheese icing over the warm rolls and serve immediately.