In a small bowl, whisk all the dressing ingredients together until combined. Taste and add more salt if needed, then set aside.
In a large bowl, combine the sliced cabbage and apple slices. Pour the dressing over top and toss to combine.
Place in the refrigerator for at least 30 minutes to allow the flavors to develop before serving. Store in a tightly sealed container in the refrigerator for up to 4 days.