Got a stash of leftover chocolate to use up? This building site chocolate biscuit cake is a firm favourite for a reason — it’s a no-bake recipe, it’s genuinely easy to make with kids, and the “building site” decorating idea (complete with chocolate walls, buried jelly tot treasure and toy diggers) makes it a brilliant birthday cake for any child who loves trucks, tools or getting stuck in.
If you can’t use up your chocolate straight away, just remove all the packaging and pop it in the freezer until you’re ready to bake.
Makes 16 portions
Ingredients
- 500g digestive biscuits (or similar)
- 100g unsalted butter
- 100ml golden syrup
- 75g caster sugar
- 50g cocoa powder
- 1 packet of jelly tots (or similar)
- 1 bar of chocolate that you can break into blocks
Method
1. Take 2 large heavy-duty sandwich bags and put one inside the other. Fill the inner bag with the digestive biscuits and bash them with a rolling pin or wooden spoon until crushed — a great job for letting kids get some energy out!
2. Get a big, heavy-bottomed saucepan and measure the butter, golden syrup, caster sugar and cocoa powder straight into it. Put the saucepan on a medium-low heat on the hob and stir occasionally.
3. Line a springform cake tin really well with cling film (a 21cm tin works well). Line a baking tray with cling film too.
4. Once the mixture in the saucepan has turned to liquid and the sugar has fully dissolved, pour in the crumbled biscuits. Stir well until they’re completely coated. Take two-thirds of the coated biscuit mixture and press it firmly into the lined cake tin. Cover with cling film, leave to cool to room temperature, then chill in the fridge for about an hour.
5. Take the remaining third of the biscuit mixture and spread it out on the lined baking tray. Break it apart with a fork — this will be your “rubble.”
6. To assemble: line a large board or tray and tip the chilled cake out onto it. Sprinkle the biscuit crumbs from the baking tray over the top, add the jelly tots (buried treasure), build a wall from the chocolate blocks, and position toy trucks or diggers wherever you like.
Frequently Asked Questions
Can I make this cake ahead of time?
Yes — the base cake keeps well in the fridge, covered, for a few days once set. It’s a great one to make the day before a party and decorate on the day itself.
Do I need to bake this cake?
No, this is a no-bake recipe. The only heat needed is for melting the butter, syrup, sugar and cocoa together on the hob.
Can I swap the jelly tots or chocolate bar?
Absolutely — use whatever small sweets or chocolate you have on hand. It’s a great way to use up surplus chocolate from Easter, Christmas or a birthday.
How should I store leftovers?
Keep the cake covered in the fridge and eat within a few days. The biscuit base can also be frozen without the decorations if you want to make it further ahead.
Related Articles
If you enjoyed this, you might also like:
- Jellybean Rainbow Cake
- Spaghetti & Meatballs Cake
- 12 Birthday Cake Ideas
Looking for more fun food ideas?
Browse our full collection of kids’ cake recipes and party food ideas for more inspiration — no baking skills required for most of them!
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