I love this photo! It makes me so hungry just looking at it! ^_^ It also feels like this could be on a professional site or in a magazine for food.
I think you have composed this shot wonderfully! Having the whoopie pies at different distances really adds depth to the photo and this makes it pleasing to the eye. Having the lighter colours of the whoopie pies against the dark tone of the plate is also intriguing. Then having that against the light colour of what I think is the table is great!
I also like how you've included the jar of jam. It adds a little more character to the photo and is a nice touch to have as it matches with how you have the jam in the whoopie pies. The fact that it looks home made is very cute too.
The photo feels very well balanced in the placing of the subjects, the colours, the composition and with lighting. Like I said earlier this is definitely professional food mag material!