I received several recipes for carrot mug and were very similar. Minor differences, for example, in the addition of milk, yogurt, sour cream, kefir or a combination of two of these ingredients. Spices were also omitted somewhere and somewhere varied. Sugar was some more or less, sometimes even a combination with agave syrup. So I made a merger and passed the final recipe. But I think it is clear to you that if you do not have yogurt, you can use the sour milk. If you like working with healthier alternative sweeteners, here are some of them. But they differ in sweetness, so the amount needs to be adjusted. Agave syrup is moderately sweetish. If you do not want to go in this direction, or if you get your favorite syrup, use traditional sugar, the cake will still be.