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 mixture. Spoon crumble mixture over fruit. Bake at 375F for 15-20 minutes. Serve warm with vanilla ice cream or whipped cream.