Cook pasta according to your liking, adding peas to water during last 4 minutes of cooking time. Drain well.
In large skillet, cook bacon until crisp. Remove bacon from skillet and crumble. Remove all but 2 tablespoons bacon fat from skillet. Sauté garlic in skillet for 1 minute. Add pasta sauce and simmer over low heat.
Pour sauce over spaghetti and peas; toss gently. Sprinkle with crumbled bacon, chopped parsley and Parmesan cheese.