In a blender or food processor, combine the vinegar, sugar, mayonnaise, onion, salt and dry mustard. Process until combined. Slowly stream in the vegetable oil. Stir in the poppy seeds.
1/4 cup white balsamic raspberry blush vinegar, 2 tablespoons plus 2 teaspoons sugar, 1 tablespoon mayonnaise, 1 teaspoon grated onion, 1/2 teaspoon salt, 1/2 teaspoon dry mustard, 1/2 cup vegetable oil, 1 1/2 teaspoons poppy seeds
Nutrition information provided is an estimate only. Various brands and products can change the counts. Any nutritional information should be used as a general guideline.