Preheat the oven to 400°F. Cut the squash in half and microwave the halves for 3 minutes to soften the insides. Remove the seeds from the squash and place the halves on a sheet pan lined with parchment paper. Drizzle 1 tbsp of olive oil on each half, season with salt and pepper, and cook for 35 minutes.
Meanwhile, brown the meat in some vegetable oil in a pan over medium heat. Add the garlic and let it cook briefly before adding the spinach.
Add the heavy cream, cream cheese, and parmesan to the pan and cook until the parmesan has melted. Then taste the creamy minced meat mixture with salt and pepper.
Once the squash has cooled, pull a fork through the pulp to create pasta 'noodles.'
Spoon the garlic parmesan beef filling into the squash, top with mozzarella, and cook at 350°F for 15 minutes.
