Fifteens Traybake

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Fifteens are a fun, no-bake traybake that originates from Northern Ireland. They're sweet, chewy and super easy to make with just 5 ingredients. Perfect for bake sales or a simple afternoon snack!

image of a white plate with 3 slices of northern irish fifteens on it

St. Patrick's Day is coming up, so I've been searching for a new recipe to try for the occasion. I started seeing this fifteens traybake ALL over my socials last week so I took it as a sign to try it! And it was seriously SO GOOD that I just had to share it on the blog! My family and I were absolutely hooked after our first bite!

Before we begin, I want to say that this is not by any means my recipe nor have I 'adapted' it. It is an old-school Northern Irish fridge cake that is made with 15 of each item plus ½ a tin of condensed milk. Without the traditional method and ingredients, they wouldn't be fifteens!

I've heard they are a super popular bakery and cafe treat in NI and for very good reason! If you've never tried these before, you're in for a serious treat. I can't wait to hear what you think. Enjoy!

Ingredients

Here's everything you need to make this recipe...

Digestive biscuits: These make up the base of the traybake, giving a malty flavour and crumbly texture. Apparently this recipe also works with crushed up Custard Cream biscuits which sounds delicious! If you're in the US, graham crackers or shortbread will also work.
Marshmallows: I cut 15 large white and pink marshmallows into 4 pieces each as this is the way I've seen all the Northern Irish people doing it, but you can use a handful of mini marshmallows instead.
Glacé cherries: You can swap these out for so many different things but I must say, I'm not particularly a huge fan of glacé cherries and I ADORED them in this traybake! The texture and flavour goes really well with the marshmallow and coconut. Some substitutions I've seen people use are Maltesers, Mint Aero chocolate and chopped Snickers bars. Yum!
Condensed milk: You'll need half of a standard-size tin, which is around 200g. This helps bind everything together nicely. Learn about the difference between evaporated milk and condensed milk here.
Desiccated coconut: I found 20g to be enough to coat the outside of the log but use more if you like.

Equipment

Food processor or rolling pin: For crushing the biscuits up into crumbs. You can also use a high-powered blender. Just make sure to crush them up finely so your log holds together nicely.
Bowl: A large mixing bowl that can hold all of the ingredients.
Sharp knife and scissors: I used scissors to cut the marshmallows into 4 and a sharp knife to cut the cherries in half.
Wooden spoon: To mix everything together.
Clingfilm: Wrapping your biscuit log in clingfilm will help it hold its shape as it sets. You can also use tinfoil.

image of a hand holding up a slice of fifteens traybake

How to make Northern Irish Fifteens step-by-step

Step 1: Add 15 digestives to a high-power blender or food processor and blitz until you have fine crumbs. Alternatively, bash them using the end of a heavy rolling pin. Once you've blitzed them, add them to a large bowl.

Step 2: Next, cut 15 large marshmallows into quarters and add them to the bowl with the crushed biscuits. Then cut 15 glacé cherries in half and add those to the bowl too.

Step 3: Pour half a tin of condensed milk (~200g) into the bowl. Mix well to combine until all the crumbs are evenly coated.

pouring condensed milk into a bowl of digestive biscuit crumbs, marshmallows and glace cherries

Step 4: Press the mixture together using your hands, then shape it into a long sausage shape. If it's too crumbly to stick together, add some more condensed milk.

Step 5: Lay a large piece of clingfilm out onto your work surface and sprinkle 20g of desiccated coconut onto it. Then place your biscuit log on top and gently roll it to coat it in coconut. Cover the log with the cling film and twist the edges to hold it in place.

Step 6: Pop it in the fridge to set for about 2 hours. Then just cut it into slices and enjoy! Traditionally, the log is sliced into 15 (hence the name) but mine was a bit on the chunky side so I cut it into 8 thick slices, then cut them in half to make 16 pieces.

FAQs

How long do fifteens last?

This traybake will last for up to 1 week in an airtight container. They are best stored in the fridge but can be kept at room temperature if you prefer a slightly softer texture.

Can I freeze this recipe?

Yes, you can freeze fifteens for up to 3 months. You can either freeze the whole log wrapped tightly in foil or clingfilm, or you can freeze slices on a baking tray until solid, then pop them into a freezer bag or airtight container. Defrost in the fridge overnight or at room temperature for an hour or so. Do not refreeze.

Why is my mixture crumbly?

This can happen if your biscuits aren't crushed finely enough but it's usually just because there's not enough condensed milk. It can be tricky to use exactly half a tin since so much of it sticks to the tin itself. If your mixture is crumbly, add an extra tablespoon of condensed milk at a time until it holds together when you press it. It should be easily mouldable and quite sticky.

What can I use instead of glacé cherries?

You can swap these out for Maltesers, honeycomb pieces, chopped Snickers bars, nuts, white chocolate chunks, or other dried fruits like apricots or raisins. Whatever you use, make sure you only use 15 pieces/chunks so they don't overpower the recipe.

Can I use a traybake tin?

Yes! To make square fifteen slices, you can press your mixture into a lined 8x8-inch tin. Sprinkle the coconut over the top before popping it in the fridge to set.

image of slices of fifteens traybake on a wooden board

More condensed milk traybakes

I hope you like this Fifteens traybake! If you make them at home, tag me on Instagram @eatcookbake_ and let me know what you think. Enjoy!