Cut the Butternut squash lengthwise in half and remove the seeds (I dry the seeds on paper towels and replant them the next year)!
Lay the halves on a microwave safe plate and dot with a generous amount of butter, sprinkle plenty of brown sugar in the center and up the neck of the squash and sprinkle with cinnamon.
Place in microwave & cover with a microwave cover (or you can use paper towels, I would stick toothpicks in the squash to raise the towels up enough so they don't stick to the sugar). Cook for 10 minutes and check the squash for tenderness. Cook for another 8-10 minutes or until all of the butter and sugar is melted and the squash is soft.
**Of course you can prepare this dish in the oven as well, the microwave is just a fast and easy alternative (and it still tastes delicious). I prepare the squash the same way and place in a deep baking dish coated well with a non-stick spray. Bake in approximately a 375 degree oven for 30 minutes then check for tenderness. You may need to bake another 10-20 minutes depending on the size of your squash.