Preheat oven to 375F. Pierce squash a few times with sharp paring knife (to let steam escape). Bake spaghetti squash for 45 minutes, or until a paring knife pierces easily through skin with little resistance. Let squash cool for 10 minutes.
Cut squash in half, lengthwise. Use a fork to remove and discard the seeds. Continue using fork to scrape the squash to get long, lovely strands. If the squash seem difficult to scrape, place squash halves cut side down, and bake for an additional 10 minutes.
Heat a large saute pan with the butter and the garlic over medium-low heat. Add spinach. When garlic becomes fragrant, add parsley, salt and spaghetti squash strands. Toss well, sprinkle in the parmesan cheese and taste to see if you need additional salt. The spaghetti squash should have a slight crunch – but if you like it softer, cover the pan and cook 2 more minutes.
