These are my modelling clay cakes!:
On the left, there is a rainbow macaron birthday cake-the middle, there is a blueberry filled kiwi layer cake-and the right, a black forest cake.
They did not, however, turn out well at the picture AT ALL-there's nothing I can do about it :(
I can show you how to make these three cakes:
They all are the same: layers, and on the outside they have cream- there is only one different part-
1. The macaron cake has macarons (of course)
2. The kiwi one has, I guess a pie crust, green bobbles and kiwi cream with chopped kiwis
3. The black forest has slivered chocolate, white pie crust, cream and cherries
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Today, I will show you how to make the easiest- rainbow macaron.
I ran out of white clay-my macaron filling might have to be colourful- :(
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Anyways, my computer video webcam lost connection, I'll show you by photo-
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RAINBOW MACARON BIRTHDAY CAKE:
Materials:
Pink, orange, yellow, green, blue, and white clay
A needle or wooden pointed stick
Scissors or craft knife (really, anything that cuts)

1. Roll equal pieces of clay into balls, then flatten them so all of them are the same size.

Stack them. I guess that's the most straightforward.                2. At this point, use your scissors/ craft knife or whatever you have and cut a wedge out. Slowly, I might add, so it doesn't smudge.

Kind of like that.            3. Then, drape it around your cake (correction, layered circles.) If the width of your pink wrapped strip is not wide enough, get for clay and roll it into a line, then wrap it around.

Flatten the rolled strip, maybe use your needle to scratch lines in like a pie crust.

If you want, you can keep the slice you cut out, or not- if you do, roll the pink clay over it also-for this tutorial, I won't. 

4. Maybe a short video won't hurt. I'll try to show you to make the macarons.

Meh. It doesn't.

OK, so, like in the beginning, roll out three MINI balls of clay and flatten them. Your colour choice. Stack them. By the way, you need five macarons, six if you use the extra slice. Then, use your needle and scratch around the top. Place them on your cake.

5. Lastly, scratch designs on your cake. Swirl and dot the inside and outside. 

You're done! :)