Toss apples with 1/4 c. brown sugar and 2 T. flour; place in a greased 8-inch microwave-safe, deep-dish pie plate.
In a bowl, combine oats, cinnamon and remaining brown sugar and flour.
Cut in butter until crumbly; sprinkle over apple mixture.
Cover with waxed paper.
Microwave on high 6-8 minutes or until apples are tender.