In medium saucepot, heat eggs and enough water to cover by 1 inch to a boil over high heat; reduce heat to medium-low and simmer 10 minutes. With slotted spoon, transfer eggs to bowl filled with ice and cold water; let stand 4 minutes or until completely cooled. Peel and chop eggs.
In large skillet, cook bacon over medium-high heat 5 minutes or until crisp, stirring occasionally; transfer to paper towel-lined plate.
In medium bowl, whisk mayo, sour cream and sugar. Makes about 2 cups.
In bottom of 4-quart glass trifle or deep bowl, spread lettuce; sprinkle with salt and pepper. Layer bacon, tomatoes, eggs, peas, cheese and onion over lettuce; spread mayo mixture over onion. Makes about 12 cups.
Cover salad and refrigerate at least 2 or up to 6 hours; serve garnished with cheese and/or parsley, if desired.