Preheat oven to 400 degrees.

Place squash with cut side up in greased baking pan.

Place one teaspoon butter plus one teaspoon brown sugar in each acorn half.

Cover squash with aluminum foil and bake until tender, approximately 30 minutes.

Scoop cooked squash out of shells, leaving 1/4 inch thick shell.

Mix cooked squash, pineapple, 1 tablespoon butter, and nutmeg. Beat until smooth.

Spoon mixture into shells; heat at 425 degrees for approximately 15 minutes.