Preheat the oven to 400 degrees F.
Cut the squash in half widthwise and scrape out the seeds with a spoon.
Slice a small piece off the bottom so that the squash lays flat and does not roll.
Using a fork, poke holes in the top of the squash.
Add 1 teaspoon of butter and 1 teaspoon of brown sugar to each half.
Put the acorn halves on a sheet pan and bake for 40 minutes.
Sprinkle cinnamon and garlic salt
Baste the top and inside with the melted butter mixture every 15 minutes.