Step 1: In a large bowl or stand mixer, combine the warm milk and 1 teaspoon of granulated sugar. Sprinkle the active dry yeast over the top and let it sit for 5-10 minutes until foamy.
Step 2: Add the remaining ¼ cup granulated sugar, mashed bananas, eggs, and melted butter to the yeast mixture. Mix well.
Step 3: Gradually add 4 cups of the flour and the salt, mixing with a dough hook on low speed or by hand until a shaggy dough forms. Add remaining flour as needed, a little at a time, until the dough is soft, slightly sticky, and pulls away from the sides of the bowl.
Step 4: Knead the dough for 5-7 minutes on medium-low speed (or 8-10 minutes by hand) until it is smooth and elastic.
Step 5: Lightly grease a large bowl with cooking spray or butter. Place the dough in the bowl, turning once to coat. Cover with plastic wrap and let rise in a warm place for 1 to 1.5 hours, or until doubled in size.
Step 6: While the dough rises, prepare the filling. In a small bowl, combine the softened butter, brown sugar, and ground cinnamon. Mix until well combined and spreadable.
Step 7: Once the dough has doubled, gently punch it down. Turn it out onto a lightly floured surface and roll it into a large rectangle, approximately 18x12 inches.
Step 8: Evenly spread the cinnamon-sugar filling over the entire surface of the dough, leaving a small ½-inch border on one of the long edges.
Step 9: Starting from the long edge opposite the border, tightly roll the dough into a log. Pinch the seam closed to seal.
Step 10: Using a sharp knife or unflavored dental floss, cut the log into 12 equal slices (about 1.5 inches thick).
Step 11: Arrange the rolls in a lightly greased 9x13 inch baking dish, leaving a little space between each. Cover loosely with plastic wrap or a clean kitchen towel and let rise again in a warm place for 30-45 minutes, or until puffy.
Step 12: Preheat your oven to 375°F (190°C).
Step 13: Bake the cinnamon rolls for 25-30 minutes, or until golden brown and cooked through. If they start to brown too quickly, you can tent them loosely with foil.
Step 14: While the rolls are baking, prepare the cream cheese frosting. In a medium bowl, beat together the softened cream cheese and unsalted butter until smooth and creamy.
Step 15: Gradually add the sifted powdered sugar, beating until smooth. Stir in the vanilla extract. Add milk or cream, one tablespoon at a time, until the frosting reaches your desired consistency.
Step 16: Remove the baked rolls from the oven and let them cool for 5-10 minutes. Spread the cream cheese frosting generously over the warm rolls.