how would you go about building an onion dome like on st basils cathedral?

not that i'd be making a cake like that any time soon. i've just always wondered.

http://images.nationalgeographic.com/wpf/media-live/photos/000/060/cache/russia-st-basils_6026_600x450.jpg

also, is it possible to do something that large in blown sugar?

I did a replica of that building. For the onion domes I used a ball shaped polystyrene and just molded the fondant around it to give me the onion shape.

Here is my cake

AIts beautiful I love it! I eventually want this to be my wedding cake that's why I'm asking

AAny ptger suggestions?

You could use a Hershey's kiss mold. It's not exactly the same shape but close.

http://www.ebay.com/bhp/hershey-kiss-mold

AI like it, I've never seen those before

AI've done it with polystyrene and rice krispie treats.

any body else have any pictures?

The person who made this cake carved styrofoam into dome shapes:

This shows pix of making onion domes with styrofoam balls and aluminum foil:

http://www.craftsforkids.com/projects/1300/1308/1308_1.htm

Some of these are cakes (some are real buildings, some are Legos, at least one is a teapot....):

https://www.google.com/search?q=onion+dome+church+cake&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&hl=en&tbm=isch&source=og&sa=N&tab=wi&ei=Q3yuUejhBZPzqwGQ3ICIBA&biw=1372&bih=756&sei=6HyuUaq_J5GCqgHSnYD4DQ#um=1&client=firefox-a&rls=org.mozilla:en-US%3Aofficial&hl=en&tbm=isch&sa=1&q=cake+st.+basil%27s+cathedral&oq=cake+st.+basil%27s+cathedral&gs_l=img.3...278684.284667.12.284986.21.20.0.1.1.0.203.3041.1j18j1.20.0...0.0...1c.1.15.img.Bzq72JJB6wU&bav=on.2,or.r_qf.&bvm=bv.47244034,d.aWM&fp=8c06593309d4a108&biw=1372&bih=756

AI love the teapot!!! I've searched and searched and didn't get most of the pictures you sent. Thankyou!

lol. i always search st basil cake on google image. i must be a bad googler :P.

the results i get are for the recipe for jewel cake.