Preheat oven to 450°F.
Drizzle eggplant halves with EVOO, salt and pepper, and place cutside down on a baking sheet. Cut head of garlic to expose cloves at ends, drizzle liberally with EVOO, salt and pepper. Wrap in foil and place alongside eggplant. Roast 40-45 minutes.
Char peppers over open gas burner flame. Transfer to a bowl and cover, until cool enough to handle. Peel and seed the peppers, then roughly chop.
Bring a pot of water to a boil and salt the water. Cook spaghetti 10-12 minutes or until al dente. Reserve 1 cup of starchy cooking water before draining.
Scoop eggplant flesh from the skin and add to a food processor with the roasted garlic and peppers.