Combine orange juice and vanilla. Set aside. Slice bananas lengthwise and place cut side up in four buttered baking dishes. Combine flour, oatmeal, brown sugar, nutmeg, and salt. Add butter. Using a pastry blender or two knives, blend until mixture resembles small peas. Drizzle bananas with orange juice. Spoon crumble mixture over fruit. Bake at 375 for 15-20 min. Serve warm with vanilla ice cream.