Place top oven rack in the center position and pre-heat oven to 400°F. Line a large, rimmed baking sheet with aluminum foil or a Silpat™ baking sheet. Set aside.

Trim the top and bottom off of each spaghetti squash to create a flat surface. Sit the squash upright and slice down the middle with a sharp knife. Scoop out the pulp and seeds with a spoon without piercing all the way through the squash. Save the seeds for roasting if you choose.

Brush the edges and inside of each squash half with olive oil. Sprinkle with the garlic powder and season to taste with salt and black pepper.

Place the squash, cut side down, on the prepared baking sheet. Cook until the squash is for fork-tender about 40 minutes.

When the squash is almost ready, melt the unsalted butter in a large skillet. Add the garlic and sauté until fragrant, about 30 seconds.  Add the shrimp, and season to taste with salt and black pepper. Cook, stirring frequently until the shrimp is warmed through and opaque, approximately 2-3 minutes.

Remove from heat and set aside. Keep warm.

Remove the squash from the oven and cool for several minutes. Once cool enough to handle, flip over each squash and carefully “shred” the inside with a fork to create spaghetti-like strands, leaving the shredded squash inside the squash shells.

Evenly divide the contents of the skillet, including the remaining melted butter, between the spaghetti squash halves. Sprinkle with the chopped parsley and gently toss to combine. Top with some freshly grated Parmesan cheese and serve immediately.