First, bake the spaghetti squash by cutting it in half and scooping out the seeds. Then place it scooped side down on a rimmed cookie sheet with ½ cup water.
Bake at 350 degrees for 30 min.
Once cool, use a fork and scrape out the squash. It will look like spaghetti noodles. Set aside.
In a large saute pan, cook the ground beef over medium high heat with some salt and pepper.
Add in the onions and cook until transparent.
Once the ground beef is browned, drain off the grease and add in the spaghetti sauce, sour cream, parmesan cheese, and italian seasoning and stir well.
Next add in the spaghetti squash and mix together until well combined.
Pour the mixture into a greased 9 x 13 inch pan and sprinkle with mozzarella cheese.
Bake at 350 degrees for 30 minutes with a piece of foil covering over the top of the pan.
During the last 5 minutes, remove the foil so that the cheese browns slightly.
Let cool for 10 minutes before serving.
Recipe by Smashed Peas & Carrots at https://smashedpeasandcarrots.com/baked-spaghetti-squash-casserole-recipe/