Preheat oven to 400 degrees Fahrenheit.
Cut the acorn squash in half and scoop out the seeds.
Place cut-side down on a microwave-safe dish; cover and microwave for 10-12 minutes, or until tender.
Flip squash over so it is cut-side up. Place 1/2 tablespoon of butter in the center of each half.
Cover and microwave on high for 2-3 minutes.
While the squash is in the microwave, cook noodles according to package directions.
In a large sauce pan over medium heat, melt remaining butter and stir in the flour.
Whisk in the milk until ingredients are thoroughly combined.
Stirring frequently, cook until mixture thickens.
Remove from heat. Add cheddar cheese and stir until mostly melted.
The acorn squash should be about ready now.
Caution: Be careful, as the squash is going to be very hot.
When the squash is tender, remove it from the microwave.
Using a pot holder if needed, scoop out the insides of the squash and stir in to cheese mixture.
Fold in the pasta until evenly coated.
Pour into greased 9″x9″ dish. Sprinkle bread crumbs and mozzarella cheese on top.
Bake for 15-20 minutes.