Building block cake decorations

(19 ratings)
Lego cake decorations


  • 70g modelling paste
  • 70g ready-to-roll fondant
  • 10g black fondant
  • Red, yellow, green, blue food colour pastes
  • Cornflour for dusting
  • 1tbsp royal icing sugar mixed with a dot of water to make glue

How clever are these building block cake decorations? They're simple to make and perfect for jazzing up any cake or cupcake - and they look just like real LEGO! They're the perfect way to top cakes for kids' parties too.

Learn how to make your very own edible building blocks with our step-by-step picture recipe.

Stack them high, arrange them in an organised fashion on top of your cake or personalise with a matching name tag.

The kids are going to love them!

Recipe by Victoria Threader


Step 1

Knead the fondant and modelling paste together and colour to classic colours. You will need: 30g red, 30g grey (white paste with a dot of black fondant), 30g green, 15g blue, 15g yellow and leave 10g white for the lettering.


Step 2

Roll the green paste to 2mm thick and cut a 68mm circle.


Step 3

For the studs, you can use either use a 4mm circle plunger or a plain piping tube. Victoria likes to use the plunger as its much faster than the piping tube.


Step 4

Roll the green fondant out to 3mm thick and brush the underside with a touch of water, this helps the studs stick when you plunge them on to the disc. Line them evenly all over the disc until itís full up.


Step 5

Use the 58mm circle cutter to cut a disc. This gives you a cleaner edge.


Step 6

Roll the red paste to 8mm thick and cut rectangles with a sharp knife. Use a Lego brick to guide the size.


Step 7

Use a 4mm circle plunger to add the studs onto the tops of the bricks.


Step 8

Cut small squares from the yellow paste and add the studs.


Step 9

To make a name decoration, roll the paste out to 2mm thick and cut a 58mm disc. For the lettering, print out your chosen font and text from your computer and cut the letters out to make templates.


Step 10

Roll the white paste out to 2mm thick and using the alphabet templates, cut around with a sharp knife.


Step 11

Dust the counter with a touch of cornflour, black fondant can be quite sticky so this will help it not stick to the counter. Roll it out to 2mm thick and with a brush of water stick the letters onto the top and trim around the edge with a sharp knife.

Step 12

Repeat with the yellow paste and then stick to the red disc with a brush of water.


Step 13

Ideally these could do with drying overnight. Cardboard cake boxes are good but nothing airtight or they will go soggy. The next day, use a dot of royal icing to stick the bricks to the toppers and then place the finished toppers on to your cakes.

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Average rating

  • 4
(19 ratings)

Your comments

L Hunt

Where did you find the 4mm circle plunger? I can only find 6mm searching on the internet.


My daughter and I did a lego cake so my husband made a mould for us


No problem. I'd love to see them when you're done if you'd like to share them on Victorious Cupcakes on Facebook? Good luck ~ Victoria


Great! Thanks! I should be able to make me a week in advance then :-).... Means I don't have to panic tying to get them done day before :-) thanks for your help!


Hi Trier! These keep really well in cardboard cake boxes (or shoes boxes if you don't have one) They will keep for up to 6 months. They wouldn't freeze well though, as moisture would make them droop. Hope that helps :-)


Anyone know how long these keep for or if they can be frozen?


My kids would probably try to build things with these Legos, but then my kids are 18 and 20 years old. lol

Penny miller

So clever,look like real Lego on top.

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