Preheat oven to 350 degrees. Line a baking sheet with foil and set aside.
Microwave each acorn squash for 90 seconds before slicing. After skin has softened slightly, cut acorn squash from root to tip. Remove seeds and pulp and place face down on baking sheet. Bake for 30 minutes.
While acorn squash is cooking, prepare sausage and apple mixture. Using a saute pan, brown sausage over medium heat. Drain any excess oil and return sausage to pan.
Dice apples and add them to pan with sausage over low heat. Combine and cook apples slightly.
When acorn squash has finished cooking, plate by adding 1/2 TB butter in each acorn squash half and sprinkle 1 tsp of brown sugar on top of squash. Fill each squash with sausage and apple mixture.