Preheat oven to 350 degrees. Grease a round 12-inch cast-iron skillet, pour in caramel and sprinkle with walnuts. Set aside until ready to use.
To make the rolls: In a small saucepan combine the milk and butter on low heat until butter has melted and the milk is warm, 120 degrees. In the bowl of a stand mixer, pour the milk mixture and sprinkle the yeast over it. Let sit for about 5 to 10 minutes until the mixture is frothy and the yeast is activated.
Using a dough hook, begin mixing the yeast on low. Add in the bananas and egg until combined. Slowly add the flour, sugar, baking powder and salt until a dough has formed and is sticky to the touch. Transfer dough to a lightly oiled bowl and cover with a towel. Place in a warm area until the dough has doubled in size, about 1 hour.
Roll the dough out on a lightly floured surface using flour as needed to about 16x12 inches long and 1/4 inch thick. Brush melted butter over the dough. Spread the mashed bananas and sprinkle with cinnamon and sugar. Working from the long edge, begin to tightly roll the dough to the other end. Cut the dough with unscented/unflavored floss into 1-inch pieces.
Place the rolls swirl side up into the prepared pan and cover with a towel. Place in a warm area, and let the dough rise again for 30 minutes or until they double in size.
In a medium bowl, blend together cream cheese icing ingredients.
Bake rolls for 35 to 40 minutes until golden brown and fluffy. Let the rolls cool slightly before turning out. Drizzle with cream cheese icing and enjoy!