Gather all ingredients and preheat your oven to 375°F (190°C).

Line a baking sheet with aluminum foil for easy cleanup.

Place the acorn squash halves on the prepared baking sheet with the cut sides facing down.

Bake for approximately 1 hour, or until the squash is tender when pierced with a fork.

Remove the squash from the oven, carefully turn the halves cut-side up, and allow them to cool slightly.

Leave the oven on for the final baking step.

While the squash cools, heat a large skillet over medium-high heat.

Add the sausage and cook, stirring frequently, until browned and crumbly, about 5 to 7 minutes.

Drain and discard any excess grease.

Add the celery, mushrooms, and onion to the skillet.

Cook, stirring occasionally, for 5 to 10 minutes, or until the celery has softened and the vegetables are tender.

Remove the skillet from the heat.

In a large mixing bowl, beat the egg until smooth.

Add the sour cream and Parmesan cheese and stir until well combined.

Add the sausage and vegetable mixture to the bowl.

Mix thoroughly until all ingredients are evenly incorporated.

Spoon the filling evenly into the roasted acorn squash halves.

Press the filling gently into each cavity to ensure it is well packed.

Divide the filling equally among all squash halves.

Return the stuffed squash halves to the oven.

Bake for approximately 20 minutes, or until the filling is heated through and lightly golden on top.

The egg, sour cream, and Parmesan will help bind the filling while creating a rich, creamy texture.

Remove the stuffed squash from the oven and allow it to rest for a few minutes before serving.

Serve warm as a complete meal or alongside a simple green salad.

This Sausage Stuffed Acorn Squash combines sweet roasted squash with a savory filling of sausage, mushrooms, celery, onion, Parmesan cheese, and sour cream. The creamy filling contrasts beautifully with the tender squash, creating a comforting and satisfying dish perfect for autumn and winter meals.

Hearty enough for a main course and elegant enough for entertaining, this recipe is a wonderful way to showcase seasonal squash.