For the Dough:

1. In a small bowl, combine warm milk and active dry yeast. Let it sit for about 5 minutes, until the yeast becomes foamy.

2. In a large mixing bowl, combine melted butter, sugar, mashed banana, and eggs. Add the yeast mixture and stir until well combined.

3. Gradually add flour and salt, mixing until a dough forms. Knead the dough on a lightly floured surface for about 5-7 minutes, or until smooth and elastic.

4. Place the dough in a lightly greased bowl, cover with a damp cloth, and let it rise in a warm place for 1-1.5 hours, or until it doubles in size.

For the Filling:

1. In a small bowl, combine softened butter, brown sugar, cinnamon, and mashed banana (if using). Mix until smooth and spreadable.

Assembling the Rolls:

1. Preheat the oven to 375°F (190°C). Grease a 9×13-inch baking dish or line it with parchment paper.

2. Punch down the risen dough and transfer it to a floured surface. Roll it out into a rectangle about 1/4 inch thick.

3. Spread the cinnamon-banana filling evenly over the dough.

4. Starting from one edge, roll the dough tightly into a log. Pinch the seam to seal the roll.

5. Slice the log into 12 even rolls and arrange them in the prepared baking dish, leaving some space between each roll.

6. Cover with a cloth and let the rolls rise for an additional 30 minutes.

7. Bake for 20-25 minutes or until golden brown and cooked through.

For the Glaze:

1. While the rolls are baking, whisk together powdered sugar, milk, vanilla extract, and a pinch of salt until smooth.

2. Once the rolls are out of the oven, drizzle the glaze over the warm rolls.