Combine first 3 ingredients in an 11 x 7-inch baking dish coated with cooking spray.
Lightly spoon flour into a dry measuring cup; level with a knife.
Combine flour, oats, coconut, sugar, ginger, and salt in a bowl; cut in butter with a pastry blender or 2 knives until the mixture resembles coarse meal.
Add 1/3 cup oat mixture to banana mixture, stirring gently to combine.
Sprinkle remaining oat mixture over banana mixture.
Bake at 375 for 30 minutes or until lightly browned and bubbly.