Preheat the oven to 400°F. Line a baking sheet with parchment paper.

Place the spaghetti squash on a cutting board and slice 1-2 inch rings all the way across the spaghetti squash, keeping the rings as even as possible.

Carefully place the squash rings on the baking pan with space between each. Melt 1 tablespoon of butter. Brush the tops of the squash with the melted butter.

Heat the remaining 2 tablespoons butter in a large skillet over medium heat. Add the garlic and crushed red pepper and cook until fragrant, about 30 seconds. Add the shrimp and cook until opaque and pink, about 2 minutes per side. Remove the shrimp from the pan and set aside in a bowl.

In the same skillet, add the spinach and stir until it wilts, about 1 minute. Stir in the vegetable broth and lemon juice and simmer until slightly reduced, 2 minutes.

Return the shrimp and any juices from the bowl to the skillet along with the spaghetti squash strands and carefully toss to combine.

Serve with lemon wedges, parsley and parmesan cheese, if desired.