Banana Dough:

1. Activate Yeast: Heat the milk to 110°F. Sprinkle yeast on top and let it rest for 10 minutes.
2. Combine Dry Ingredients: In a large bowl, mix flour, sugar, and salt. Add cubed butter and use a pastry blender or your hands to cut the butter into the flour until it resembles coarse crumbs.
3. Add Wet Ingredients: Add the milk/yeast mixture, beaten egg, and mashed bananas to the dry ingredients. Mix on low speed until a dough forms, then knead on medium speed for 5 minutes.
4. First Rise: Preheat oven to 200°F. Place dough in a greased bowl, cover with a towel, and let rise in the warmed (then turned off) oven with the door cracked for 1 hour.

Cinnamon Banana Filling:

1. Cream Butter and Sugar: Beat butter until smooth. Add brown sugar and cinnamon, and mix well.
2. Roll and Fill Dough: Roll the dough into a ¼-inch thick rectangle. Spread the cinnamon filling over the dough and top with sliced bananas.
3. Shape Rolls: Roll the dough into a log and cut into 12 even rolls.

Bake:

1. Second Rise: Place rolls in a greased 9×13 inch pan, cover, and let rise for 20 minutes. Preheat oven to 375°F.
2. Bake: Bake for 28-33 minutes, or until golden brown.

Cream Cheese Icing:

1. Cream Cheese and Butter: Beat cream cheese and butter until smooth.
2. Add Sugar and Vanilla: Add powdered sugar and vanilla extract. Mix until creamy.

Frost and Serve:

1. Frost the cooled cinnamon rolls with cream cheese icing and serve warm.