Solar System Cake Recipe

Here you will find the recipe for the Solar System cake by our very own presenter Matt K.

space party birthday cake

Space Cake (Not That Kind of Space Cake) With Planets Inside


Note: The cake in these photos is a triple layer cake. All of the ingredients lists below are for single portions but for this cake, I tripled the cake ingredients to made three layers, and doubled the chocolate buttercream as I needed a lot! I just made one lot of cake pops but personally I think more were needed, but I’ll add an extra note on that later.


Cake Pop Ingredients

120g                                                                 Butter

150g                                                                 Caster sugar

1tsp                                                                   Vanilla extract

2                                                                       Medium eggs

180g                                                                 Self raising flour, sieved

4tbsp                                                                 Milk

Splash           Food colouring. I used red, yellow, blue, and green (and made orange as well).


Note: This recipe supposedly makes 40 cake pops. I got about 30 out of it. Perhaps I overfilled some of the mould a bit. Each segment wants to be level with the top of the mould. See photo further down.

solar system cake pops mixture

Cake Pops – Method


  1. Grease the cake pop mould, top and bottom (this job really sucks).


  1. Cream the butter and sugar until it is light and fluffy (That’s cooking lingo. I mashed the hell out of it with a wooden spoon until it was mixed). Add the vanilla extract and eggs (break them first, you don’t want shell in there) and mix well. Add some flour and milk and keep mixing until you have added all of the ingredients.


  1. Divide the mix into equal portions for however many colours you want to use in the cake pops. I did five colours (using red and yellow to make orange), but didn’t weigh the portions. I just guessed it. Add food colouring to each portion and mix well. Start with a little and then add more to reach your desired colour. Don’t add too much though as you don’t want to make the mix go runny, or turn people’s mouths blue!


  1. Spoon the mixture into the bottom cake pop mould (the one without the holes). Each pop wants to be full to the level top. When the top half of the mould goes on, this will be empty, giving the mix room to raise. I did a bit of blue and a bit of green for earth, and then swirled it gently (not completely) with a cocktail stick. For the sun I did orange and yellow, Mars is red and a bit of orange etc.


  1. Place the mould in a preheated oven at 180oC, gas mark 4, for 15-20 minutes. Test the cake pops by pushing a cocktail stick through one of the holes in the top of the mould. If the stick comes out clean, they’re ready. Leave them to cool and once they are, remove them from the mould and trim off any excess around the middle.
solar system cake step by step

Cake Ingredients

225 g            Unsalted butter or margarine (I used Tesco baking block)

225 g            Caster sugar

175 g            Self-Raising Flour, sieved

50 g              Fine dark cocoa powder

4                   Medium eggs


Cake – Method


  1. Squish the butter/margarine/baking block in a bowl until it isn’t hard as a rock any more. I left it on the counter for a few hours first, which made it much easier. Once mixed, add one egg and quarter of the flour and mix some more. Keep adding one egg and quarter of the flour until it’s all in and mixed very well. Finally, add the cocoa powder and mix in gently (or it’ll go everywhere!) I wanted the cake to look black so I also added a boatload of black food colouring. As far as I can tell it made absolutely no difference which is why I left it out of the ingredients list above!


  1. Grease your cake tin (I used an 8” (20cm) round tin. Spoon in enough mixture to completely cover the bottom of the tin once it is spread around. Then add some of the cake pops. (Note: I used nine in each layer which looked like a good amount, but as you can see from the pictures of the cross section, you can’t see that many. Maybe you should add more but that may also adjust the cooking time and the amount of mixture actually needed per layer. Sorry I can’t offer any better input on this part. I’m not a baker, just a guy who had a go and was mostly successful!) Spoon in the rest of the mixture around the cake pops being sure to fill in all the gaps, but also be gentle around the cake pops as they may damage if you nudge them too hard.


  1. Place the tin in a pre-heated oven at 180oC, gas mark 4. Bake for…well, I have no idea. My recipe always says 20 minutes but that’s nonsense. It’s usually more like an hour. I start to check it at around forty minutes. Give the tin a very gentle shake in the oven. If the mixture still wobbles, leave it in and keep checking it every 10-15 minutes. If it looks set, take it out and try the cocktail stick test as mentioned in the cake pops bit. Leave the cake to cool and (this is just a me thing) wrap it in cling film to keep it from drying out until you decorate it. I do this as I usually bake it the night before I ice it.
solar system cake preparation

Chocolate Buttercream Ingredients

75 g              Unsalted butter

175 g            Icing sugar

45 g              Fine dark cocoa powder

20 – 30 ml     Milk


Chocolate Buttercream Method


  1. Mash the butter (you know the drill by now). Sift in the icing sugar and mix the two together, adding the milk to create the consistency you desire. Sift in the cocoa powder and mix well. Again, I added loads of black food colouring. It made no discernible difference what-so-ever.


  1. Nope! Easy one, this. Just the one step.


Decoration Ingredients

3 blocks        Black icing sugar, ready to roll

1 block          Yellow icing sugar, ready to roll

White sprinkles

White sugar stars

Icing sugar and water



space party photoshop ideas
  1. If your cake is like mine, the top of it rose into an impressive point! As impressive as it is, we don’t want that so use a bread knife to slice it off as evenly as possible (or use one of those cake levelling thingies. I had one but it broke). Spread a layer of the chocolate buttercream on top of the layer, and then put the next layer of cake on top of that. Keep doing this until you have run out of cake layers, and then spread a final thin layer of chocolate buttercream on the top. Then also cover all around the sides of the cake with a thin layer of buttercream. This sticks the icing on.


  1. Open all three blocks of black icing and roll them out into a huge flat circle. For anyone who has never decorated a cake before, this bit is a bugger. Cover your work surface with icing sugar and roll your icing here. Roll it out a bit, then gently lift it to make sure there’s enough icing sugar still underneath or it will stick to the surface. Add more if needed. Keep doing this bit by bit (which, unfortunately, gets harder the bigger it gets) until you have rolled it out enough. If you aren’t swearing loudly by this point, you’re better than I am!) Drape your icing over the cake and do your best to make it neat. I can’t help you here, I’m fairly crap at it. I just make sure the front looks good and the back is passable!


  1. Roll out some of the yellow icing and cut out a circle (I used a plastic bowl from Ikea as a template). Stick to the top of the cake using any remaining chocolate buttercream. If you have run out, mix some icing sugar with a tiny amount of water to make a slightly runny icing. This can be used as a glue to stick things to the cake and will come in very handy later.


  1. Roll out some more yellow icing into a long thin shape. Trim along the length until it’s about 2cm wide, and then cut this strip into triangles. Stick the triangles around the yellow circle on top of the cake. It’s a sun!


  1. This next bit is down to what you can find in the supermarket. I found a set of sprinkles in the supermarket that had four different compartments. One compartment had small star shapes in different colours so I poured them out and just used the white ones. Another compartment had thin sprinkles, again in different colours, so I just (sloooowly) sorted out the white ones. The stars stick onto the cake easily with the icing sugar glue mix, and the thin strands can just be pushed through the icing. Time-consuming but effective!



Final Notes


  1. If you aren’t baking the main part of the cake with the cake pops inside straight away, freeze the cake pops until you need them. Just make sure they are defrosted again before you add them to the cake. I didn’t do this as I baked it all in the same day. It’s just a tip I read.


  1. While I don’t know too much about allergy advice, you can easily make this cake dairy-free (mine mostly was). Simply substitute baking block for butter (Stork or supermarket own brand is fine) and milk for soya milk. We have Alpro Growing Up Milk in our house anyway which is quite sweet, so I used that.
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Space Party: Step by Step Solar System Cake by Matt K

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