How to make fake cupcakes – tutorial

by Sayraphim on April 25, 2012

I’ve been working on a new project investigating guerrilla kindness, called For you, stranger. You can see the project itself here  and you can read a blog post about the first drop here. It was such a simple project to do I thought I’d share how to do it today. Feel free to make your own and spread the joy!

One of the things I love about this project is that baking is traditionally a woman’s role and this project uses mostly building materials, traditionally in a man’s sphere. In fact, during the icing of the cupcakes, I did wonder how much more neatly a tradie would have done it.

There’s a bit of work involved and there also needs to be drying time in between the stages. This batch took me a couple of days all up, but most of that time was drying time for the cakes while I did other things.

Things you’re going to need:

  • A can of expanding builders foam (easily obtainable at a hardware store)
  • A tub of lightweight spac (spackle) filler/plaster filler (the stuff builders use to fill holes in drywall/giprock, again easily found at a hardware store) I found 100g did about 20 cupcakes and in the end, I needed two tubs to ice all my cupcakes.
  • Acrylic paint  in cake colours (I used light brown and darker brown, I like chocolate cake) and icing colour
  • Cupcake paper patty pans
  • Decorations for cupcakes – I used glitter and a bead, but you can use anything you like
  • Newspapers to cover your work surface
  • gloves and old clothes to wear while you’re makin’ (if you’re messy)
  • some thick cardboard (like a bit of box) for the bottom of the cupcakes
  • a craft knife, box cutter, stanley knife or the like

Ok, ready?

Step 1: The first thing to do is to spread out the cupcake patty pans. The builders foam needs to be used in an open area, so if you can, do this step outside. The foam expands quite a lot, all over, so if you just put it in the pans, the bottom of the cupcake will expand too, making for cakes with a rounded bottom that rocks all over the place. So you’ll need a bit of cardboard in a circle in the patty pan first to give your cake a flat bottom to rest on.

Step 2: Put on your gloves. Things could get sticky. Grab your builders foam and read the instructions on the can. Once the can of foam is opened, you need to use it up within about a month otherwise it hardens and becomes unusable. You can use it all up today however, if you have enough patty pans. I got about 40 cupcakes out of the can, aim for a few more patty pans though, as I over filled mine accidentally. Only fill your patty pans about 3/4s. The foam expands quickly at first, but then will continue to expand, so dont be tempted to go back and top up if you think it hasn’t expanded enough. This comes from experience 🙂


The tutorial I read online suggested that you use a cupcake/muffin tin to keep the shape right as the foam expands, but I found I didn’t need it, they did fine on their own. Once the cupcakes are poured, they need to set, which takes different time depending on which foam you used. Again, refer to your can for all the details. Don’t be disheartened that, at this stage, they don’t look much like cupcakes. I promise they’ll look awesome by the end.

Step 3:  Ok, so in the picture the cupcake is all lumpy and alien-landscape looking. Luckily, the foam is really easy to carve. Don’t be too worried about getting it perfect, by the time the spac filler icing covers the top half, any little divots and wobbles will just look like cake. So get carving and aim for jsut a basic cup cake dome shape

Taa daa! Cupcake shape!

Step 4: Next step is to paint the cake to make it look more like.. well, cake.

 You can use acrylic paint for this, which can be bought at any craft store and some hardware stores too. To go for a realistic-ish cake colour, I used a light tan-yellow colour and a dark brown colour, swirled them together and painted with that. I didn’t mix the paint thoroughly, which meant that both colours showed through in different patches, which added to the cake effect. You could just paint it one cake colour though, and that would be perfectly fine too.

I folded the patty pan down a little so I could get as low as possible with the paint. As you’ll notice from the photo, I didn’t paint the top of the cake, I figured that the icing would cover that. Later, I worried that the icing wouldn’t cover over all of the white, so I went back and painted the white bit cake coloured too. Next time I do it, I’m going to paint the whole thing first time. That way your icing artistry isn’t dictated by where you’ve painted the cupcake. Again, you’ll need to wait for the paint to dry before you do the next step, this wont take too long though, depending of course on how thick you painted it and how warm your environment is.

A range of cupcakes, before I decided to go back and paint the tops too. You can almost see the rage of cakey colours created by the two paints.

Step 5: Icing and making pretty!

 So I bought a plastic container at a charity shop for this step – once you use something for these type of non-food purposes you shouldn’t let it go back into the kitchen. The utensil in the spac filler is a small cake knife I also bought at the charity shop which was very useful for icing the cakes.

Put the spac filler in your container and stir it a little bit. Sqooge in some paint, I used red and blue to create this purple, mainly because I had no purple. I also needed to add a little water (about a tablespoon) – this thins the spac filler out a little, which makes it easier to stir and ice. You get a nice sheen on it once the water is added and then it acts pretty much like icing.

Ok, onto the icing itself.

After a couple of attempts, I figured out the best way to ice it for me, but experiment and find out what works for you. My system was to blob a bit at the top of the cake, then

I used my cake knife to smeer the icing down the cake to the level I wanted it (I chose to leave a bit of cake showing at the bottom, otherwise it might jsut look like a patty pan filled with icing)

Then I lightly smoothed down all the ridges and furrows from the last step.  The cake is now iced! I did try piping icing on, with a disposable piping bag, but it used up a lot of icing and looked pretty bad, so I didn’t bother with it again.Looking back, if I added a bit more water it might have worked better.

To finish off, I sprinkled glitter on the cupcake and placed a red bead at the top. I made sure that each of the bead’s two holes were accessible so I could thread the tag through later. I did this step outside, but only because it was a nice day. Spac filler can be used inside with no problems.

Now you need to leave the cupcakes to dry. Because of the thickness of the spac filler, it took about 24 hours to dry.

Step 6: At this stage, the cupcakes are finished and done. This next step is only really for if you’re making the cupcakes to leave out or give as gifts. This is the tagging stage.

I contacted Holly from Two Cheese Please, a talented lady who carves stamps, to make me a special stamp for my tags.

I cut the paper stamps into tag shapes, punched a hole through them and threaded them through the bead on top of each cupcake. Then I wandered around the city and left them out for people to find

And this is how happy they made at least one lady 🙂

That’s it! Done! Phew, now I want some real cake.

If you do make some cupcakes, either for street art, guerrilla kindess or any other reason, I’d love to see them!

{ 2 comments… read them below or add one }

Robyn Slakey November 30, 2012 at 5:41 pm

I make cupcakes too. Did a 15 ft. totem for the state fair. Also did “Cupcakes Across America” you might like to see. It’s all on my FB page.

Sayraphim January 6, 2013 at 4:17 am

Hi Robyn, your cupcakes looked great! Thanks for letting me know about them.

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