Peppermint Slice
Peppermint Slice is a classic Scottish tray bake with a crunchy chocolate biscuit base, creamy peppermint icing filling, and a smooth chocolate topping. It’s an easy no-bake recipe with a refreshing minty twist.
It’s no secret how much I love a tray bake. They’re some of the easiest recipes to make, and everyone has a favourite. Mine is a toss-up between Fudge Slice and Mars Bar Slice. One of the most requested tray bakes we get, though, is Peppermint Slice.
This super simple tray bake is a big favourite with my sons. Both have recently discovered mint-chocolate ice cream and will always choose a Mint Aero when allowed to pick a sweetie. Taking after their Granny in that department, who has always been a fan of Mint Poppets, a box of Bendicks at Christmas, and a Peppermint Cream (or two).
As far as tray bakes go, this one takes a little bit of time investment, purely because you need to let the layers set in between. But that aside, it’s one that anyone can manage, and with a bit of crushed Mint Aero on top, it’s sure to wow anyone who you share it with…that’s if there’s any left to share!
Top Tips for Peppermint Slice:
• No digestives? No problem: If you can’t get digestive biscuits where you are in the world, simply swap them for Graham Crackers.
• Crush your biscuits: For easy biscuit crushing, whack the digestives into a sealable sandwich bag and hit it with a rolling pin. This saves you from getting crumbs all over your kitchen and also means you don’t need to wash your rolling pin at the end.
• Press Firmly Into the Tin: Use the back of a spoon to press the base mixture down firmly into the corners and edges of your tin. This helps the Peppermint Slice hold together properly once it’s set.
• Check your peppermint extract: Some extracts are stronger than others. Start with less, then taste the filling before adding more.
• Keep the layers chilled: Make sure each layer is firm before adding the next; otherwise, they may melt into one another, and you won’t get the lovely layered effect.
• Decorate or keep it simple: Crushed Mint Aero adds texture and flair, but the slice is just as delicious with a plain chocolate top.
• How do you cut chocolate tray bakes neatly: Start by letting your tray bake set completely in the fridge, and then come to room temperature again. Then score the top of the chocolate where you want to cut it first. Next, cut right through the tray bake with a large, sharp knife, with confidence! It won’t be perfect every time, but it does get easier with practice.
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Peppermint Slice
EQUIPMENT
- 20x20cm Baking Tin (8 inch)
- Spatula
INGREDIENTS
For the Base
- 225 g Digestive Biscuits (Graham Crackers)
- 1 tbsp Caster Sugar (Superfine Sugar)
- 115 g Butter or Block Margarine
- 3 tbsp Cocoa Powder
- 50 g Dark Chocolate
For the Filling
- 340 g Icing Sugar (Powdered Sugar)
- 3-4 tsp Hot Water
- 2-3 tsp American Peppermint Extract
- Green Food Colouring (optional)
For the Topping
- 300 g Dark Chocolate
- Crushed Mint Aero (optional)
INSTRUCTIONS
- Generously grease and line a 20x20cm (8-inch) baking tin with greaseproof paper, and set aside. In a pan, melt the butter/margarine, sugar, cocoa and chocolate.
- Meanwhile, crush the disgestive biscuits, either in a sandwich bag with a rolling pin, or blitz in a blender. Add to the melted mixture and stir until combined.
- Transfer the base mixture to your prepared tray and using a wooden spoon, press the mixture into the tray, ensuring you get right into the corners and have an even finish. Place the base into the fridge to chill for 1 hour.
- Once the base has cooled, prepare the filling but sifting the icing sugar into a large bowl. Add 1 tsp of hot water at a time until you have a spreadable consistency; 3-4 tsp of water should be enough but add more or less as required.
- Add the peppermint extract and green food colouring (optional) to the icing and mix until well combined. Spread the icing evenly over the biscuit base and return to the fridge for another 1 hour to set.
- Once the filling has set, remove from the fridge and set aside. Over a bain marie (or in short bursts in the microwave) melt the dark chocolate before pouring and evenly spreading on top of the filling. If desired, top with some crushed Mint Aero.
- Allow the peppermint slice to set in the fridge for at least 1 hour but ideally overnight. Once set, cut into your desired size.
IMPORTANT NOTE:
All my recipes are developed using a digital scale and the metric system (grams and millilitres). Cup measurements are available as a conversion but these, unfortunately, won’t always be as accurate. For best results, I always recommend baking with a digital scale.
RECIPE NOTES:
- Storage: Keep Peppermint Slice in an airtight container in the fridge, where it will stay fresh for up to 1 week. It can be kept at room temperature for a short time, but the layers hold up best when chilled.
- Make Ahead: This is a great recipe to prepare a day or two in advance, as the flavours develop and the layers firm up nicely in the fridge.
- Freezing: Peppermint Slice can be frozen, but the texture of the filling may alter slightly once defrosted. Cut into portions, wrap individually, and store in a freezer bag for up to 3 months. Defrost in the fridge overnight before serving.
- Substitutions:
- Biscuits: Digestives work best, but Graham crackers or Rich Tea biscuits are good alternatives.
- Butter/Margarine: Either works in the base. Ideally, you want to use a block margarine, but as it will be melted, a spread maragarine can be used in a pinch.
- Chocolate: Dark chocolate balances the sweetness, but milk chocolate or a mix of both can be used.
Peppermint Slice is a no-bake tray bake made with a chocolate biscuit base, a creamy peppermint icing filling, and a dark chocolate topping. It’s a classic Scottish favourite, often topped with crushed mint Aero chocolate for extra flavour.
It’s made in three simple layers: a biscuit and chocolate base, a peppermint-flavoured icing filling, and a chocolate topping. Each layer is chilled before adding the next to create clean, firm slices.
Yes. Use a vegan margarine, a dairy-free dark chocolate, and make sure your biscuits are vegan-friendly.
This usually happens if the chocolate sets too hard. Try removing your tray bake from the fridge for a short while before cutting. Score the chocolate where you want to slice before cutting right through. Make sure you use a very sharp knife, and be confident. And you can try sitting your knife in some hot water before cutting (being sure to dry the knife before actually cutting) to help it slice straight through the chocolate.
Free-from & Vegan:
Gluten-free: To make this a gluten-free Peppermint Slice, swap the digestives for a gluten-free biscuit alternative. Most supermarkets have their own versions, or you could use gluten-free Graham crackers in the US. Be sure to use a gluten-free chocolate and check all other ingredients allergen lists.
Dairy-free: Use a dairy-free margarine in the base, and choose a dairy-free dark chocolate for the topping (any are naturally vegan). Skip the Mint Aero for decorating and leave plain. Also, check that your biscuits are dairy-free.
Vegan: To make this a vegan Peppermint Slice, follow the dairy-free steps above. Also, check that your biscuits are vegan, and ensure the peppermint extract doesn’t contain animal-derived ingredients.
Nut-free: This recipe is naturally nut-free, but always double-check your chocolate and biscuits when baking for allergies.
Egg-free: No eggs are needed, so this peppermint tray bake is egg-free, but always double-check your individual ingredients, particularly the biscuits.
N.B. Any advice or suggestions to make recipes “free-from” or vegan are purely that – suggestions. Please be careful to double-check all ingredients individually, taking extra caution when serving to those with allergies & intolerances.
For more info on common food allergies, please see food.gov.uk | For more info on coeliac disease, please see coeliac.org.uk | For more info on a vegan diet, please see vegansociety.com
Just made this ,can’t wait to try tomorrow. Love your recipes
Sorry but this didn’t end well, the chocolate set rock hard and pushed all the icing out when I tried to hacksaw it into squares! Too much faffing about for me, I’ll stick to your Tiffin recipe!
I’ve made this quite a few times now, it’s perfect when I remember to cut it an hour after setting the chocolate, but even when I forget it still tastes great!
I’ve made this 4 times now, the same thing happened to me on the second one. I find that chilling for about 3 hours once the icing is on to make sure it’s really well set helps. Once the chocolate topping is on, chill for about 8 minutes, and take it out of the fridge and cut it while the chocolate is still soft, making is easier to cut, then put back in the fridge overnight.
Just add some vegetable oil through the top chocolate layer, than it won’t set rick hard and you can slice easily
Add a little oil to the chocolate topping when melting. It will make it easier to slice without affecting the taste.
Use a hot knife! I put a sharp knife in a mug of hot water and it cuts through the hardened chocolate no bother
Oh my word!! Fantastic recipe. By far the most delicious mint slice I’ve ever tasted and I MADE IT MYSELF!!! I used half milk chocolate and half dark. I cut it after 2 hours in the fridge (as I couldn’t wait any longer to try it) and it cut well. If I’d have left it over night I think the same would have happened as did with Karen. Will be making this again and again!!
Dip your knife into a bowl of hot water before cutting, do much easier, just glides through the chocolate.
I am from the US but love Scotland and the treats. Please help me know what a digestive biscuit is as I search for a substitute here. Could it be like a graham cracker?
Not 100% sure, but do you get ‘Marie’ biscuits? Digestives are pretty sweet, crumbly biscuits.
Yes, the nearest equivalent is Graham crackers
It’s a semi sweet biscuit made in Scotland. You might get them in Walmart it’s mcvities Digestive biscuit here look on web
Yes it is almost the same . Go for it x
I made this…went a bit crazy with the cocoa powder, read the recipe wrong and used 50gs instead of a couple of table spoons. Regardless it was lovely and turned out great!!!!
Made lastnight had to add a little extra water for a softer fondant and double cream in the choclate but let’s say this… Simply gorgeous
Surely the water for the icing sugar should be TBSP no TSP?
Agreed!
Can this be frozen ahead of eating?
Butternut cookies or ‘Nice biscuits’ can be used if you can’t find digestive biscuits for the base.
Tried this and its absolutely delicious. Big hit with everyone.
This recipe is soooo delicious. Everyone loves it. Thank you for posting it.
DELICOUS! Super nice but used half the amount of chocolate for the top – still amazing. Tried an orange version of this : just used orange food colouring and orange essence for the icing and put orange aero on top. So so good would recommend definitely. And no baking too! Simply delicious. My family will be tired of this because I’m going to make it so much!
Ooh the orange sounds super cool I made one with pink icing, strawberry flavour and freeze dried strawberries on top – bliss
Great recipe! I didn’t add the sugar to the base as the rest was sweet enough and it turned out great. Cut it after only a short chill then left it overnight and separated into squares in the morning. Packaged it up for sweet treats for my sons nursery teachers! Thanks!
So glad I saw your post with the Peppermint Creams which led me to this recipe. This was a favourite treat of my late mums and brings back very fond memories of my mums ‘baking days’.
Thank you ….will be trying the recipe out
Made this for the first time yesterday, have just cut up successfully and had a piece wuth a cuppa, absolutely scrummy,,I love a mint and chocolate combination so this recipe was a great find, love dates too so making that next.
Iv just made this waiting for the hour for the bottom biscuit layer in the fridge so I just noticed I forgot to put the 50g of melted chocolate in to the biscuits so hoping it still works il update you all soon tonight
Update- I didn’t do well lol the mint was to strong and to runny I think I need less water and to add the chocolate to the biscuit part but first time doing it but il Di better next time lol
This recipe tasted AMAZING. But I do suggest when you are crushing the digestives you should use a food processor/ blender so that it is nice and in small pieces. It was hard to cut into, so I recommend putting it in the fridge for only an hour after pouring chocolate.