WHISK egg yolks, lemon juice, water, sugar, mustard, salt and pepper in small saucepan until blended.
COOK over very low heat, stirring constantly, until mixture bubbles in 1 or 2 places. REMOVE from heat immediately; let cool 4 minutes.
POUR mixture into blender; COVER. With motor running on high speed, ADD oil slowly, in a thin stream; BLEND until mayonnaise is thick and smooth. TURN off blender occasionally to scrape down sides with rubber spatula. REFRIGERATE, covered.
Add minced herbs or garlic for more flavor.