Roast your spaghetti squash. has a nice step by step guide! I follow their Roast it Whole Method. Preheat your oven to 375 degrees. Place squash on baking pan and roast in oven for 40 minutes. Check. Squash is done when it forks easily with a fork. Depending on the size of your squash, it could take up to an hour and you may want to rotate it from side to side halfway through.
After squash cools enough to handle easily without burning yourself, cut off both ends then slice in half lengthwise. Scoop out pulp and seeds.
Scoop out your spaghetti squash strands and place in colander over a bowl. Sprinkle squash with salt and let sit for 15 - 20 minutes to draw out water.
Place squash in small round baking dish.
Stir in your Vegan Cashew Pesto (or preferred pesto recipe).
Slice tomatoes and layer on top of squash.
Sprinkle with chopped basil.
Combine breadcrumb, nutritional yeast, onion powder, garlic powder and oregano and place the mixture on top.
Cover with foil and bake at 350 for 30 minutes