Finely shred the cabbage and place it in a large mixing bowl.

Finely slice the red onion and add it to the bowl.

Peel and grate the carrot, then add it to the mixture.

Roughly chop the fresh parsley leaves and mix them in.

In a separate bowl, combine the white sugar, kosher salt, mayonnaise, apple cider vinegar, Dijon mustard, ground black pepper, and additional sugar to create the dressing.

Pour the dressing over the cabbage mixture and toss until evenly coated.