Tutorial : Polymer clay realistic cake texture with baking soda

So wow, long time no post again, apologies.

It seems I’m catching up on all my bumming around time aahah, but don’t worry, I’m crafting a lot tonight so that I can get some regular tutorials up


So I’m actually really excited for this post. From the title you can tell what the tutorial is on right?
I’ve actually known about this technique from when I first started from the youtuber “GentlemanBunny”

I tried out it out ofc, but it didn’t end up working. Then about a week ago, I found this website


And so here I am trying it out for you guys ^^

Let”s go !




  • Softener
  • TSL or Fimo deco gel
  • Baking soda (Bicarbonate of Soda)
  • Small container for mixing (in my case, a finished face cream container)
  • Foil
  • Polystyrene
  • Tool for mixing
  • Clay of choice

Soaking the clay

  • Take the clay that you want to be the ‘sponge’ colour and place it in the container
  • Poke some holes in it so the softener can work its magic faster
  • Cover the clay with softener and let it sit
  • Every so often, mix the clay around

At first, I mixed the clay around a lot in the softener and this actually made the dissolving process a lot slower. After I gave up and just let it sit, when I mixed it again, all the clay dissolved much quicker.
As for the softener amount, because my container was slightly larger than I liked it to be, I didnt completely cover my clay up to the top. It was kind of half way up the clay and I just flattened it out. If you can, try to use a smaller container.

Completely dissolved

  • Mixmix
  • And then it’ll look like this once dissolved
  • Add some TLS or deco gel, the amount is completely up to you but make sure you put enough… I think mine was about 1tsp ? Sorry I did a lot of guesstimation

Testing clay

  • I took it out and ‘brushed’ it on the foil and baked it. This is to test if it would fully bake and be pliable
  • And yes it was.. lol

Making cake tin

  • For a cake tin, cut out a template onto the polystyrene block
  • Wrap it in foil
  • Cut the edges neatly
  • Place in the oven for baking.

So apparently, when polystyrene is heated, it shrinks. I didn’t know about this method for making cake tins until that day….
Anyway, I put it on for 130 degrees (celcius) and after about 3-4 minutes, the shrinking process started. Then it only took about another 5- 10 seconds before I took it out.

You can take the ‘cake tin’ out at any point once its shrinks. It just needs to be small enough for you to take it out of the foil without changing the shape.

Baking soda

  • Picture of the shrunken polystyrene circle
  • Adding baking soda
  • I added probably about 2 tablespoons. In the earlier link where I found these instructions, it doesn’t really tell you how much to add. I just added enough until the clay mix was thick like real batter.

If you have enough materials, please feel free to experiment with the amounts of softener : clay : baking soda ratio. I think as along as the mix is semi thick, it’ll rise


  • Pour ‘batter’ into the mould
  • Bake at normal clay instructions ( 130 degrees C , for about 15 minutes)
  • As you can see, it actually rose !SDKFJKFSHHKJ ! It looks realistic right ?

Rising took about 5 minutes in

Complete cake

  • Here it is out of foil
  • You can see the slightly shiny edges from the foil
  • I trimmed the edges of the cake and you can clearly see the realistic texture ( please enlarge the image)
  • The top really looks like a real vanilla cupcake right ?

MOre images

  • Some more images of the cake and texture (please enlarge)

close up

  • I had enough batter to try again and I did
  • This time, I didn’t trim the top of the ‘cake tin’ that much because I knew it would rise
  • However, you can still tell it rose out of the foil
  • Also, because I put in a lot more of ‘mixture’ and baked it for the same amount of time, the clay didn’t completely bake through

It looked exactly like an underbaked cupcake. You can see that when I tore the foil off,  the bits of clay stuck to it like batter would to a cupcake liner

Second try

Close up of the clay


  • Here I cut this cake apart to look at the texture because it was failed away.
  • This texture is also perfect for bread as well.


And that’s it !

An interesting outcome is that the clay actually is flexible. Like its quite soft and when you squeeze it, it just goes back to its original shape again..

This is actually quite an expensive way to make the realistic cake texture but here it is !

I hope you enjoy this, and actually try this out because it’s such a genius idea ,,

Thanks for reading !



7 thoughts on “Tutorial : Polymer clay realistic cake texture with baking soda

    • That’s mostly likely because you didn’t bake it long enough..
      You can see that it happened to me on my second try because I put it in the same amount of time as the first one when it should have been longer.

      • Moon says:

        I tried again and baked it for 18 minutes with the same amount of baking soda. It didn’t rise at ALL for some reason.

      • What is your liquid to baking soda ratio ? Since I don’t have a set recipe to make this work, I put in a lot more baking soda that I probably should have..

        I also tried to make sure not to put too much liquid clay in just case it would have gotten too thick ><

        I'm sorry if I can't help a lot because I've only ever done this once. I think I'll try again soon and see what happens ,,

    • This cake texture is actually quite squishy even after baking because it’s kind of like diluted clay ,, even after months the cake I baked is still squishable ahaha

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s