First preheat the oven to 375F. Then spray a 13x9 inch baking dish with cooking spray. Then peel, halve lengthwise & seed the squash. Then cut into 1/2 inch thick slices. Then arrange in the baking dish with the slices overlapping kind of.
Next in a 2 quart saucepan melt the vegan margarine over medium heat. Lower the heat to low, add in the garlic & cook for about 2 to 3 min. Stirring occasionally until garlic is soft & vegan margarine is infused with the garlic. Do not let the vegan margarine turn brown.
Next in a small bowl mix the bread crumbs,nutritional yeast & 1 Tbsp. on the garlic vegan margarine mixture. Then brush the squash with the remaining garlic vegan margarine mixture. Sprinkle with salt, pepper & bread crumb mixture.
Then bake uncovered for about 30 to 40 min or until squash is fork tender. Then increase the temperature to 425F. Then bake for about 5 to 10 mins or until lightly browned. Then sprinkle with the parsley just before serving.