Preheat oven to 375°.
Lightly spoon flour into a dry measuring cup; level with a knife. Combine the flour, 1/4 cup granulated sugar, and brown sugar in a bowl; cut in butter with a pastry blender or 2 knives until mixture is crumbly. Add nuts; toss well.
Combine the apple and remaining ingredients in a large bowl; toss well. Spoon apple mixture into an 8-inch square baking dish or 1 1/2-quart casserole. Sprinkle with the crumb mixture. Bake at 375° for 45 minutes or until golden brown.