I saw this sweater on Facebook a little while ago and if I had a little one the right age for it I would definitely knit one right up.
The Annie Sweater by Melanie Rountree has puffy sleeves, can be knit cropped or long and is sized from newborn to age 12. It looks like the perfect thing to wear over twirly dresses.
It is worked in aran weight yarn and includes positive ease to account for growth and so it can be worn over dresses or other clothes. The designer has rated it intermediate.
You can get a copy of the pattern from Ravelry.
[Photo: Melanie Rountree.]