Wash and pierce whole squash. Microwave on high 10-12 minutes, or until squash feels soft to touch and according to the size you use. Let stand about 5 minutes.
cut in half, and remove seeds. Place cut side up in a baking dish (size depends on how much you are cooking). If you cook more that 1 squash you will have to vary the amounts of the other ingredients or just to your taste.
Fill centers of squash with sliced or diced apples (I dice). Top each with 1/2 of each of the brown sugar and cinnamon. Dot the tops with cut up butter.
Cover with plastic wrap and place back in the microwave on high for 6-7 minutes or until the squash and apples feel tender.