Creamy Blue Cheese Dressing

Ingredients
1/4 cup buttermilk
1/8 teaspoon garlic powder
1 cup mayonnaise or salad dressing*
2 to 3 ounces crumbled blue cheese (1/2 to 3/4 cup)
1 tablespoon finely chopped onion
1/2 teaspoon Worcestershire sauce
Dash bottled hot-pepper sauce
2 tablespoons dairy sour cream*
1/8 teaspoon seasoned salt