Preheat oven to 425 degrees F. Coat a large baking sheet with cooking spray.
In a large bowl, combine bananas, sugar and cinnamon. Mix well and set aside.
Unroll pie crusts onto a flat surface.
Using a ring mold, make circles in the dough. Put the banana mixture on the pie dough and place another round on top. Pinch around the edges of each section to seal. Transfer the empanadas to the prepared baking sheet and make slits in the top of each to allow steam to escape. Place the baking sheet into the preheated oven and bake until crust is golden brown, about 8 to 10 minutes. Remove the baking sheet from the oven and place the empanadas on a platter. Serve with ice cream or sprinkle with powdered sugar, if using.