Add the cabbage, carrot, and onion to a large colander. Sprinkle with salt and toss well between your fingers. Place over a bowl and let it sit and marinate for about an hour.
Rinse the cabbage mixture under cold running water. Allow to drain for 15 minutes.
If you're not making the salad right away you can put it in a ziploc bag and refrigerate it until you're ready to make the salad, up to one day ahead.
In a large bowl, add the buttermilk, olive oil, vinegar, caraway seeds, mustard and honey. Whisk until well blended.
Add the cabbage mixture and the bacon to the bowl and toss well until the cabbage is fully coated in the vinaigrette.
Season with salt and pepper to taste.