Prepare the Dough:

• In a large bowl, combine the flour, sugar, salt, and yeast.
• In a separate bowl, mix the warm milk, melted butter, egg, vanilla extract, and mashed bananas.
• Pour the wet ingredients into the dry ingredients and stir until a soft dough forms.
• Knead the dough on a lightly floured surface for about 5 minutes, until smooth and elastic.
• Place the dough in a greased bowl, cover with a clean kitchen towel, and let it rise in a warm place for about 1 hour, or until doubled in size.

Prepare the Cinnamon Swirl:

• In a small bowl, mix the granulated sugar and ground cinnamon.
• Spread the softened butter evenly over the rolled-out dough.
• Sprinkle the cinnamon sugar mixture evenly over the butter.

Assemble the Rolls:

• Roll out the risen dough on a lightly floured surface into a rectangle about 12×18 inches.
• Spread the softened butter evenly over the rolled-out dough.
• Sprinkle the cinnamon sugar mixture evenly over the butter.
• Starting from the long side, tightly roll up the dough into a log.
• Cut the log into 12 equal-sized rolls.

Bake the Rolls:

• Place the rolls in a greased 9×13-inch baking dish, cover with a clean kitchen towel, and let them rise for another 30 minutes.
• Preheat your oven to 350°F (175°C).
• Bake the rolls for 20-25 minutes, or until golden brown.

Prepare the Glaze:

• In a small bowl, whisk together the powdered sugar, milk, and vanilla extract until smooth.
• Drizzle the glaze over the warm rolls before serving.