In a small saucepan, combine cider vinegar, sugar, celery seed, salt, black pepper, and olive oil. Whisk until sugar dissolves and simmer for 3-4 minutes. Remove from heat and cool.

In a large mixing bowl, toss the shredded cabbage and grated carrots together until well mixed.

Pour the cooled dressing over the cabbage and carrot mixture. Stir gently to coat the vegetables evenly.

Cover the coleslaw and refrigerate for at least 2 hours, preferably overnight.

Before serving, stir to redistribute the dressing and adjust seasoning if necessary.