Peel and grate the carrots into a large bowl.
Add the grated apple and raisins if using.
In a small bowl, mix the mayonnaise, yoghurt, lemon juice, sugar, salt, and pepper to make the dressing.
Pour the dressing over the carrots and mix well until evenly coated.
Cover and refrigerate for 30 minutes to 1 hour to allow the flavours to develop.
Serve chilled as a refreshing side dish.