Heat oven to 350°F. Lightly spray cookie sheets with cooking spray.
In large bowl, beat sugar, peanut butter and butter until light and fluffy. Stir in bananas, vanilla and eggs until well blended. Stir in flour, oats, baking soda, cinnamon and salt; mix well.
Onto cookie sheets, drop by rounded teaspoonfuls 2 inches apart. Flatten slightly with back of spoon. Bake 8 to 14 minutes or until light golden brown. Immediately remove from cookie sheets to cooling rack. Cool completely. Sprinkle with powdered sugar.