I just saw this cupcake and it is so beautiful...
http://www.flickr.com/photos/smallthingsiced/4352324882/in/set-72157604435903660/
My question is how to get the top of cupcake round and puffed up like this?

That is so pretty! I use to make some similar to these in a bakery where I worked. I used the large cupcake tip (not the one that makes the swirl design but the one with a plain large open hole) and piped on a large amount of buttercream. Then I would kind of roll the top of the cupcake to form the icing in a mound. I hope that this makes sense. I am not very good at giving directions.

I looked at some of her other photos, and in this one http://www.flickr.com/photos/smallthingsiced/4348775794/in/set-72157604435903660/ she explained that the cupcake had a "generous helping of...buttercream topped with a circle of fondant lightly dusted with lilac lustre [dust]".

so very pretty, wish I had enough time to make those kinds of cupcakes.
Jodi

Could also put firm ganache under the fondant...

thanks all for your help