How we made a LEGO Birthday Cake

We love inventing new birthday cakes when it comes to those special occasions and this time around we decided to theme it around everyone’s favourite toy – LEGO.

How we made a LEGO Birthday Cake

There are a few ways to go about making a LEGO cake, but our way was a little more complicated than others, although hopefully you’ll agree that it was worth the effort.


The main part of the cake was simple enough and made using our chocolate sponge recipe. This was then covered in ready rolled red icing and we printed out the name using the LEGO font (you can download this here), before duplicating it using icing. To finish the name we copied the LEGO logo colours.

So what about the edible chocolate bricks? Well as you can imagine, this took a little more time, however, we feel it was worth the effort just for the look on everyone face when we showed the kids they could eat them.

To make the LEGO chocolate you can either buy a mould from Amazon or like us you can make your own. The reason we made our own was for authenticity, as most of the moulds for sale are much larger than actual LEGO bricks, even those sold by LEGO themselves. To make the mould we got a large LEGO based plate and built a large square, two bricks deep. Within this square we placed random bricks, leaving a gap of two between each. Once built we then mix up some liquid silicone (purchase 1KG’s worth here) and poured it into the space and once dry it created the mould as seen below. The LEGO bricks within simply pop out, leaving the perfect mould for LEGO chocolate, ice cubes or whatever else you can think of making.


What’s so special about our chocolate bricks is that they are actually stackable. As you can imagine, if you were to put melted chocolate into the mould above it would have a flat bottom, however if you lightly oil a LEGO base and snap it on top of the mould, once the chocolate is dry it’ll peel away leaving you with perfectly stackable bricks as seen below.

(*Note, we made the chocolate minifigures using a LEGO ice try, you can buy one here.)


As you can see above, the bricks in the picture look very authentic, which is mainly due to the mould of course, however given that we used white chocolate we had to colour them. You cannot use a water based colour with melted chocolate, so after a bit of searching around we settled on Wilton Primary Candy Colour (purchase here), which we feel does that job perfectly. To use you simply melt the chocolate and then add a drop of the colour you want to use, give it a stir and it colours the chocolate. You’ll have to put the freshly filled mould in the fridge for a few hours until the chocolate firms, remembering to cover it with the lightly greased base to make the bricks stackable. Once firm the chocolate simple pops out. There may be a few imperfections but don’t worry about that too much – you can even use any extra as cupcake decorations if you like.

Once you have all your bricks, you can stack them on a LEGO base and be as creative as you like. Since we had a round cake we decided to build a wall of bricks around it and throw some extra in the gaps. We even had enough left over to write Travis’s name as you can see in the finished cake below.


This was certainly a fun cake to build and the great thing is, once you have the mould it’ll be simple if you ever fancy doing it again, or just making the LEGO chocolate bricks for fun.

Joe Anderson

Joe is a computer games and now food journalist. He loves to bake, cook and eat.

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