Placing the bowls on the barpan is probably not a good idea. The uneven distribution of heat could cause your stone to crack. This was a topic with this season's mousse recipe.
How about ball caps for the boys? Cut a piece of paper plate or something for the rim of the cap. Or just do a little baseball with white icing & red lacing.

 

Boys cake

Maybe they could make a mountain or volcano. What about a space ship- with attached ice cream cones?
Kristi

 

Prep Bowl Mini Cakes

The following information I got from PC when they had the Snowman Mini Cakes on Consultant's Corner....Hope it helps!!

To bake cakes, preheat oven to 350ºF. Prepare one package (9 ounces) yellow or white cake mix (for single layer cake) according to package directions. Grease and flour six Prep Bowls; evenly divide batter into bowls. Bake 20-25 minutes or until Cake Tester inserted in center comes out clean. Cool cakes 5 minutes in bowls. Carefully invert onto Stackable Cooling Rack; cool completely. If necessary, cut off tops of cakes using Serrated Bread Knife to level. If desired, one package (18.25 ounces) cake mix can be substituted for the 9 ounce package. Fill each Prep Bowl with ½ cup batter; reserve remaining batter for another use (such as a single cake layer prepared in the Nonstick Cake Pan or 12 cupcakes prepared in the Stoneware Muffin Pan).

 

suggestion

Couldn't you even use the mini fluted pan so the hole is already in the middle.Thanks for the idea I have two little girls and 4 nieces so we have many girly b-day parties.

 

mini-prep vs mini-fluted

I would think it would make the "dress" way too big in comparison to the miniature doll waist up. It would also be cheaper to use the prep bowls. (You can make more dresses with one box of mix in the mini-prep bowls than you can with the mini fluted's)

 

I like this idea. I might make up a few to put on my bridal table. Might be cute.