Weighted Companion Cube CAKE!!

Picture of Weighted Companion Cube CAKE!!
As the girlfriend of a major computer/video game geek, and a fan of portal myself, I decided to make the dear boyfriend this weighted companion cube cake for his birthday.

Note: This cake can be made with very little experience with fondant. But, I couldn't find any other way to make it without fondant, so you gotta use fondant.

Think I've said fondant enough?


Step 1: Making the Base

Picture of Making the Base
I used 2 8-inch square cake pans, and betty crocker's yellow cake mix for this cake. Just cool them until they're completely room temperature ((any heat will melt the frosting))

Aqua's Frosting Recipe?
3 Cups powdered sugar
3 tablespoons of butter.
4-5 tablespoons of COLD milk.
Mix well, add more or less milk as need be!

Frost the top of both cakes, and layer them on top of each other. Pretty easy, right? I thought so too.

Then frost along the sides as well. All this frosting will help the fondant stay in place, as well as give it a more pleasant flavor.

It doesn't have to be perfect, as it wont be what is showing.

You can add colors and/or flavors to your frosting as well. For this cake I recommend pink, as it will probably save you a step or two later!

Be sure to save some of the frosting for later, you'll need it!

loopyloop752 years ago
glogirl3 years ago
This was requested by my son, for his 15th Birthday. Thank-you so much for this instructable! (My first forage into making fondant was fairly successful)
A Companion Cube cake a made for a friends birthday =)
YOU ARE AWESOME!! Thank you so much for posting this. Will be baking for my husbands birthday in a week :)


no one ever gets me because, bec-c-c-cause.........

.....I'm different.
please tell me we don't have to throw it in the incinerator!
does an oven count as an incinerator?
cotton4 years ago
1. Dosent look like a cube
2. this is a insult to the companion cube, you killed it.
3. Nice cake :D i want sum

but seriosly, your moking its death, the cake is a lie
gageylawson4 years ago
i know i've seen that cube somewhere before...
Portal! (video game)
Ive found that an easy way to cut fondant is with a rotary cutter (i.e. a pizza cutter)
CruelLeader5 years ago

A good friend of mine and I decided to try making this cake for a birthdayparty we were invited to. We all got to know eachother at a university summerschool in game developing so I guess we all qualify as geeks.
Anyway we were all very satisfied with how the cake turned out, so I just wanted to thank you for the instructable!
In case anyone is wondering, we added some goo's from "World of Goo" to the cake, also made out of fondant, call it blasphemy!
Btw. we used a recipe for making our own fondant, mainly based on marshmallows, it was great fun :P

awesome idea with the goos, physics based games belong with other physics based games also world of goo and portal were both just amazing games
rix_1015 years ago
the cake is still a lie to me 0_o
smashbros355 years ago
Hmmm.... putting the cube in the oven looks oddly familiar...*sob* no! never again! I will not burn my pal again!!!
spraynard5 years ago
My roommate and I are both huge portal fans.  I think I'll make this for his birthday (with a little help from his wife).
halo995 years ago
This was a triumph.
I'm making a note here: HUGE SUCCESS.
It's hard to overstate my satisfaction.

Aperture Science:
We do what we must because we can.
For the good of all of us
Except the ones who are dead.

(Chorus 1)
But there's no sense crying over every mistake
You just keep on trying till you run out of cake
And the science gets done and you make a neat gun
For the people who are still alive.

I'm not even angry.
I'm being so sincere right now.
Even though you broke my heart and killed me.
And tore me to pieces.
And threw every piece into a fire.
As they burned it hurt because
I was so happy for you.

(Chorus 2)
Now these points of data make a beautiful line
And we're out of beta we're releasing on time.
So I'm GLaD I got burned think of all the things we learned
For the people who are still alive.

Go ahead and leave me.
I think I prefer to stay inside.
Maybe you'll find someone else to help you.
Maybe Black Mesa -
Anyway, this cake is great:
It's so delicious and moist.

(Chorus 3)
Look at me still talking when there's science to do.
When I look out there it makes me GLaD I'm not you.
I've experiments to run there is research to be done
On the people who are still alive

And believe me I am still alive.
I'm doing science and I'm still alive.
I feel FANTASTIC and I'm still alive.
While you're dying I'll be still alive.
And when you're dead I will be still alive.

Still alive
Still alive
nerfer1925 years ago
The companion cube cake ISNT a lie
GlaDoS:the enrichment center would like to inform you that the weighted companion cube cannot speak...in the event that the weighted companion cube does speak the enrichment center strongly advises you disregard its advice
boyzboyz6 years ago
Bleck Fondant. I Made a companion cube cake last year, 3 layers and the corners on the sides of the cube were made of cake. Took awhile to get them to stay, but frosting and toothpicks works.
DrWeird1176 years ago
Make a life sized: GlaDOS, Chell, and working Portal Gun that doubles as a cake.
daedric6 years ago
you should make the whole cube next time! mmmmmmmmmmm cake!
demonbabi136 years ago
lol i just bought my bf a companion cube poster, too bad his bday passed. I would reccomend trimming the actual cake so it is flatter. it just looks a little round at the top
Doctor What6 years ago
That's a whole lot of sugar. Sugar!
VogelYogel6 years ago
This is brilliant! After making one of the other Portal cakes on this site, I couldn't help but look for a companion cube cake, and here it is! Five stars!
craig36 years ago
does the fondant actually taste nice? I mean not while having small bits of it while making it but large pieces while eating a slice of cake cos i know icing can become quite sickening after eating alot of it
thetron6 years ago
Amazing! Thank you!