01 - Combine the sliced cucumbers and onions in a large mixing bowl.
02 - Whisk together the sour cream, mayonnaise, white wine vinegar, dill, sugar, garlic powder, salt, and pepper in a separate bowl until smooth and well combined.
03 - Pour the dressing over the cucumbers and onions. Toss gently until evenly coated.
04 - Refrigerate for at least 20 minutes before serving to allow flavors to meld.
05 - Serve chilled. Stir before serving and garnish with additional fresh dill if desired.