Pretty Easy Erupting Volcano Birthday Cake (Using Dry Ice)

Picture of Pretty Easy Erupting Volcano Birthday Cake (Using Dry Ice)

This is a cake I designed and assembled for my older son's 5th birthday.  It's pretty easy, and not that expensive (about $25-$30; $17 was the cake, so if you're a baker, even less).  It requires no specialized scientific knowledge, and is safe (enough for my 5-year-old and his friends; YMMV).  Everyone was duly impressed (if I do say so myself, which, in fact, I do), including the 'Mad Science' guy we hired as the entertainment for the party (you can see him check it out in the video- he's the guy in the lab coat behind the birthday boy).  It's my first Instructable, so constructive criticism and comments are welcome!

Step 1:

Picture of
For this cake you will need:

A cake (mine was from Costco, $17); I asked them to write on one half and leave the other half blank.  There's no reason that you couldn't bake your own, however.
Candles- traditional in my country (America)

Crisp Rice-Type Cereal, chocolate flavor (technically, I cared more about the color than the flavor).
Marshmallows- probably 2 bags, depending on the size of your volcano
(The previous two ingredients are to make the Rice Krispie Treat recipe that will be used to construct the volcano)
1 small plastic cup (mine was from Ikea ; I chose orange to enhance the lavaesque appearance)
Red or orange frosting
Dry Ice; you only need a little bit, but it sublimates quickly, so get more than you need, particularly if you are buying it on a different day than the party.  I got 10 Lbs the day before, and this was probably way too much even with test runs, etc.  5 Lbs should do it.  Google "Dry ice (your zip code)" if you're not sure where to get it.
Tongs/Gloves to handle the dry ice , and a hammer to break off chunks would be handy but not necessary.
Not pictured:
Butter (for Rice Krispie Treat recipe )
A little water
4 Plastic forks, broken to the height of the cake to support the weight of the volcano
Disposable gloves (for volcano molding)
Cooking spray oil
Plastic wrap

Dinosaurs- I bought a couple packs at the dollar store. 
Not pictured:
1 wooden skewer & hot glue gun (for pteranodon support)
Shany1204 years ago
Yummy idea! imma gonna try it!
mzpo4 years ago
abduraxman74 years ago
This turned out so well!
nhenry20054 years ago
This turned out so well!
My youngest is turning 6 in a month and loves dinosaurs.
I will so be making this cake for him!
Thanks for posting, I love this idea!
canida4 years ago
This is AWESOME!

I love the fact you've combined a store-bought cake with rice-crispie treats and dry ice - it's the perfect blend of time-saving and awesome-looking. The dinosaurs are a great bonus. Might I suggest a fudge tar pit for the next version?
bsgolob (author)  canida4 years ago
A tar pit is a great idea! I think I'd go with chocolate syrup, in keeping with the "time saving" theme. Thanks for all the nice comments, and if any of you are so inclined, you can vote for it at the top of the page in the "Party Food" contest!
spammy904 years ago
That is totally wicked! I'd freak out with joy if someone showed up with this on my 21st birthday. Props to you for being such a doting and cool (obligatory pun, sorry) father.
chinchymork4 years ago
Kids Love stuff Like this!!! Heck I love stuff Like this!!! nice job!