The best way to roast spaghetti squash so that it isn’t watery or mushy is to cut the squash in half lengthwise and scoop out the seeds. Season the inside with salt and pepper and add a drizzle of olive oil. Then, lay the halves cut side down on a foil lined baking sheet sprayed with cooking oil. Roast the squash at 400°F. for about 40 minutes, depending on the size. A small squash may only need 30-35 minutes, whereas a large one will like take between 40-50 minutes. Don’t roast it for too long or the strands will likely get mushy and more water will be drawn out.