Instructions
1Heat the oven to 400°F. Halve the spaghetti squash lengthwise (microwave it whole 3–4 min first to soften — much easier to cut), scoop the seeds, rub with a little oil, salt, and pepper, and roast cut-side down on a sheet pan 35–40 min until a fork pierces easily.
2While the squash roasts, mix the beef, panko, egg, Parmesan, garlic, Italian seasoning, salt, and pepper. Roll into ~16 meatballs and arrange on a second sheet pan.
3When the squash has ~18 min left, slide the meatball pan into the oven. Bake 16–18 min to 160°F.
4When the meatballs go in, toss the edamame with olive oil, salt, and pepper and scatter them around the meatballs on the same pan — they roast in the same window and come out blistered and crisp-tender.
5Rake the squash flesh into strands with a fork. Melt the butter with the garlic in the still-hot squash halves (or a bowl), toss the strands with it, the Parmesan, and a handful of chopped parsley if you have it, and season. Let the meatballs rest 2–3 min, then serve them over the squash with the edamame alongside and extra Parmesan at the table.