SaveSaveWhat greater birthday cake can there be than an exploding Volcano cake covered in dinosaurs!? This volcano cake is fast and easy to assemble- totally doable at home yet it will make the best impression! Edible lava, colorful dinosaurs, and delicious cake underneath. SaveSave
Why this volcano cake works
- Easy to assemble
- Products are easy and inexpensive to find!
- The entire cake is edible
- Can be done within an hour
There are 3 steps to making this Volcano cake with exploding lava.
- Make the volcano.
- Adding Lava
Step 1: Shape your Volcano
- Start by making our Rice Krispie treat recipe. (Don't worry you should have a little bit left over that you can eat. Trust me, you will want to snack on them.) This recipe is a bit extra marshmallowy meaning it will give you no problems on falling apart or holding its shape.
- Using a 16oz mason jar build up your Rice Krispie treats around the jar in the shape of a volcano. Let cool completely.
Choose a volcano covering.
I have used both
- chocolate frosting
- chocolate fondant
I prefer to use chocolate fondant, I feel that its easier to work with, less messy and looks better. But you can 100% use chocolate frosting on top of the Rice Krispies if that is your preferred topping.
- knead your fondant for a few minutes to get it malleable then roll it to about ¼ inch.
- fold it into fourths to transfer an then fold it over your volcano.
- press it gently down top of your volcano (remember volcanos are bumpy and rough its ok if you don't have smooth sides on your volcano.)
- Trim the edges and cut a hole in the top.
*If you want the simplest possible volcano use Coco Krispies and don't use any covering at all.
What is fondant and where do I buy it?
Fondant an edible icing, but in sheets! I bought mine at Walmart (just though delivery app). If you are in a Walmart store look at their party section not the baking isle.You can also buy it at Michaels and other cake specialty stores or make it homemade.
You can buy both white and chocolate fondant. I bought chocolate because it is already brown and ready to use. If you buy white fondant you can add color by kneading in food dye.
What kind of cake do I use for an exploding volcano cake?
You can make a homemade cake or a store bought sheet cake. I have done both- what is pictured is a store bought sheet cake.
Here are some tips if you choose homemade.
- If placing volcano on top of cake make it 2 layers to hold up the volcano.
- Place cake around homemade cake if you don't want to worry about volcano effecting cake.
Tips for a store bought cake:
- I prefer this cake because the frosting is a little more stable and the cake is strong enough to hold up the volcano with no issues.
- Freeze cake for about an hour then scrape off the decorations. They come off easily!
PROTIP: to smooth out the icing I run my icing spatula under hot warm water and it works perfect!
How to make your Lava for dinosaur volcano cake
You will need
- Red Jello
- Boiling water
- Dry Ice
In pitcher add your jello and boiling together. Stir for two minutes.
Assemble your volcano on or to the side of your dinosaur cake.
Pour in your Jello. Your exploding volcano works best when the jello is hot! So don't make the jello until you are ready to explode!
Add your dry ice
You can find dry ice at your local grocery store. I find mine at a Kroger store called Albertsons. There are sometimes other retailers that sell it near you. a Good way to find dry ice near you is to google "where can I buy dry ice near me."
remember with dry ice:
- NEVER touch dry ice with your bare skin.
- Dry ice evaporates. Once you buy it you need to use it with in a couple of hours. If you think it will be a few hours buy a larger block, store it in an air tight container in the freezer. That will slow down the evaporation process.
Place a sheet pan under your cake to trip the drippings of the lava.
To keep the volcano going you will need to add more warm jello and dry ice intermittently. You might want to take the volcano off the cake and set it somewhere else so you can serve cake but still have the awesome smoking volcano going.
Yes! This is a great alternative to coving with frosting or fondant!
Yes! you can use cake and place a jar inside the middle to hold the liquid jello.
YES! if you want to make this all on a larger scale just change the amount of ingredients but follow the same process
I picked up this $10 bucket of dinosaurs and they were the perfect size! not too big or too small. (I hand made the hats).
Volcano Cake with dinosaurs
- 1 16 oz glass jar
- 1 ½ sheet cake store bought
Rice Krispie Volcano
- 1 cup butter
- 2 10oz bags of mini mallows
- 10 cups Rice Krispies
- 1 pkg chocolate fondant
- 2 6oz packages of red jello
- 3 cups boiling water
- 5+ lbs dry ice break into small pieces
- In a large pan melt butter. When Melted add in marshmallows. When Marshmallows are starting to soften and expand stir in Rice Krispies.
- Place glass jar on parchment paper and build up rice kripsie mixture around it to form a volcano. Bring the Rice Krispies about ½ inch above the rim of the jar. There will be some extra Rice Krispies. you can place those in a pan and eat.
- Knead chocolate fondant for about 3-5 minutes until soft. Roll out to ¼ inch and lay over volcano. Gently press down and trim bottom. Cut hole in top over Jar opening.
- If desired freeze cake for about an 1 and then scrape off store frosting decorations. Add dinosaurs and volcano to top of cake.
- Right before ready to serve Mix jello with boiling water. Pour into jar (there will be some leftover for extra long volcano erupting opportunities) When ready add dry ice into Warm jello mixture.
Hi! Random question but do you think I could paint some “lava” and just add dry ice to the jar so I have the smoke but no mess of the jello? Or does dry ice need to be in liquid?
You have to have warm liquid for the dry ice to smoke. You could put less water in the jar so it doesn’t bubble up. But it probably won’t smoke as long. Just add more warm water to keep it smoking.
Hello, I’m planning to make this for my sons birthday. I’m wondering how much of a mess does the jello make? I’m trying to figure out where to place it and what base to put it on. Thanks
I would put it on a jelly roll pan or cake pan.
Could you make the volcano out of cake rather than rice krispies? And cut the jar into the centre.
I don't see why not!
Mum of a dino lover says
Can I ask, is it safe to eat the cake after the lava has exploded? Does the dry ice disappear totally and it's just the jello that's left? Thanks.
Yes it is safe to eat after the dry ice is dissolved. Also, the cake is made from Rice Krispies and the "lava" is inside of a mason jar.
Hello, just to clarify, do you freeze the dry ice before you put it into the jello or no? I noticed you said you froze it the first time around, but then it did not work. Just want to make sure I get this right for my son's birthday. Thank you in advance!
Sorry Alla, you can not keep dry ice in the freezer for more than a few hours or it disappears. So use the dry ice as soon as possible. This post is very old and needs to be revised, so please excuse the unclear instructions.
I'm making this exploding volcano for my son's birthday today. I prepared the Jello liquid last night and left it out at room temp, however this morning, it is very thick, almost like prepared Jello. Is this how it should be, or do I need to remake it?
if you heat the jello up in the microwave it should return to liquid form.
Did you fill the mason jar with dry ice ?
Also was it just one jello pack for how big of a mason jar ?
Drop about a handful of dry ice into the mason jar a couple minutes before serving.
And yes - 1 16oz packet of jello.
I’m going to use Coco pebbles for the volcano. We are gluten free so rice Krispy cereal won’t work for us. Plus with coco pebbles you don’t need to frost it. Win win.
Sara M says
THANK YOU so much for this - I just made this cake yesterday for my son’s 3rd birthday and I literally felt like a hero it was so awesome.
For those attempting: I used a large mason jar (32 ou) and I had to make THREE batches of rice crispy treats to build it. I bought the dry ice day of (thanks for that tip!) and also did a test run a few days before. My advice is to go big on dry ice - you’ll get more drama! I think I filled the mason jar about 1/4th full. I used one big size jello packets to be sure I had enough, and I made the jello mix shortly before - it was pretty cool though so it doesn’t need to be hot but I don’t think I would refrigerate it. If I could post a picture on here I would - it was epic!!! Thank you!!!!!!!!
A very interesting idea. I would really love to try this out. So if I understand correctly, you just make jello liquid and pour it into the volcano, add dry ice and that's it? Adding dry ice would make the jello bubble out ?I was thinking that the cold due to dry ice would make jello solidify. Please clarify.
Yes, you are correct. The liquid jello bubbles up and over the volcano.
Hi! Did the liquid jello have to be kept hot or was it room temp? Did you use any water? Thank you!
I have the same question about the temp of the jello liquid. Can it be room temp/cold??? Just wondering if I can prep it the day before or even that am?
IT looks like a great idea. I don't really understand about the cake pans/keeping the other cake separate. did you put the volcano on the board or on the pan? I would also love to see a further out picture to get a better idea of how it all looked together. Such a lot of fun!
Oh my gosh this is THe coolest!!! WAs the volcano edible after it erupted? My son is obsessed with volcanos and dinosaurs and i'm totally going to make this for him! Great idea!!!!
Hey Brittney! Haha so glad you like it, it was such a blast to make and my son was obsessed too. There's nothing wrong with eating the jello liquid mixed with liquid nitrogen. If your party go-ers are into jello liquid all over a chocolate rice krispie, more power to them :) Tag us in any pictures you take after making it, I'd LOVE to see how yours turned out!
Do you have any coloured pictures of the entire cake instead of zoomed in black and white ones? They look great, but i'd love to see the whole thing.
Hey Jen! The overhead shot of the backward L white frosted cake and the chocolate volcano sitting adjacent to it is how I presented the cake. You could rest the volcano halfway on the flat sheet cake and halfway off, or just leave it nestled right next to it. Tag us in any pictures you post, we'd love to see the final product!