In a large mixing bowl (or stand mixer bowl), combine the warm milk, yeast, and a pinch of the granulated sugar. Stir gently and let sit for 5-10 minutes until foamy, indicating the yeast is active.

Add the remaining granulated sugar, melted butter, egg, mashed banana, and salt to the yeast mixture. Mix until well combined.

Gradually add 3 cups of flour, mixing with a wooden spoon or dough hook until a shaggy dough forms. Continue adding flour, 1/4 cup at a time, until the dough comes together and is no longer excessively sticky. You may not need all 4 cups.

Transfer the dough to a lightly floured surface and knead for 8-10 minutes until smooth and elastic. If using a stand mixer, knead with the dough hook for 6-8 minutes.

Lightly grease a clean large bowl with a little oil. Place the dough in the bowl, turning once to coat. Cover the bowl tightly with plastic wrap or a clean kitchen towel and let it rise in a warm place for 60-90 minutes, or until doubled in size.

While the dough is rising, prepare the filling. In a small bowl, combine the light brown sugar, ground cinnamon, and nutmeg (if using). Set aside.

Once the dough has doubled, gently punch it down to release the air. Transfer it to a lightly floured surface.

Using a rolling pin, roll the dough into a large rectangle, approximately 12x18 inches.

Brush the entire surface of the dough with the melted butter for the filling, leaving about a 1/2-inch border clean on one long edge.

Evenly sprinkle the brown sugar and cinnamon mixture over the buttered dough, pressing it gently to adhere.

Starting from one of the long edges, tightly roll the dough into a log. Pinch the seam gently to seal.

Using a sharp knife or unflavored dental floss, cut the log into 12 equal rolls, about 1 1/2 inches thick. To use floss, slide it under the log, cross the ends over the top, and pull to cut cleanly.

Lightly grease a 9x13 inch baking dish. Arrange the cut rolls in the prepared dish, leaving a little space between each.

Cover the baking dish loosely with plastic wrap or a clean kitchen towel and let the rolls rise again in a warm place for 30-45 minutes, or until puffy and almost doubled in size.

Preheat your oven to 375°F (190°C) during the last 15 minutes of the second rise.

Bake the rolls for 20-25 minutes, or until golden brown on top and cooked through. If they start browning too quickly, you can loosely tent them with foil.

Remove from the oven and let cool in the pan for 10-15 minutes while you prepare the glaze.

In a medium bowl, beat the softened cream cheese until smooth. Add the powdered sugar, milk (or cream), vanilla extract, and a pinch of salt. Whisk until completely smooth and creamy. If the glaze is too thick, add a tiny bit more milk; if too thin, add a little more powdered sugar.

Generously spread the creamy glaze over the warm (but not piping hot) cinnamon rolls. Serve immediately and enjoy!