Preheat oven to 375º.
Lightly spoon 1/3 cup flour into a dry mea-suring cup; level with a knife. Combine flour, oats, and sugar in a medium bowl. Cut in butter with a pastry blender or 2 knives until mixture is crumbly.
Combine apple and next 4 ingredients in a large bowl. Spoon into an 8-inch square baking dish. Sprinkle flour mixture over apple mixture. Bake at 375º for 45 minutes or until golden brown.