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
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
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!
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
This recipe is soooo delicious. Everyone loves it. Thank you for posting it.
Tried this and its absolutely delicious. Big hit with everyone.