Peppermint Slice

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Peppermint slice traybake recipe. Chocolate biscuit base, peppermint cream filling with chocolate mint aero topping.

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. One of the most requested tray bakes we get though is Peppermint Slice.

This super simple tray bake is a big favourite with The Boys. 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 and a box of Bendicks at Christmas.

"Oh my word!! Fantastic recipe. By far the most delicious mint slice I’ve ever tasted and I MADE IT MYSELF!!!"

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!

Peppermint slice recipe from Baking with Granny. Mint chocolate tray bake, with peppermint cream filling and chocolate topping.

Love this? Try this:

Peppermint slice tray bake recipe. Digestive biscuit base, with peppermint fondant filling and mint chocolate topping.
Peppermint slice recipe from Baking with Granny. Mint chocolate tray bake, with peppermint cream filling and chocolate topping.

Peppermint Slice

5 from 8 votes
Course: Dessert, Snack
Cuisine: British, Scottish
Prep Time: 3 hours
Servings: 12 slices


For the Base

For the Filling

For the Topping


  • Generously grease and line a 28x18cm tray 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.
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Peppermint Slice recipe from Baking with Granny. Easy traybake, with biscuit base, mint fondant filling and aero chocolate topping.

28 Responses

  1. 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!

    1. 5 stars
      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!

    2. 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.

    3. Just add some vegetable oil through the top chocolate layer, than it won’t set rick hard and you can slice easily

    4. Add a little oil to the chocolate topping when melting. It will make it easier to slice without affecting the taste.

  2. 5 stars
    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!!

    1. Dip your knife into a bowl of hot water before cutting, do much easier, just glides through the chocolate.

  3. 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?

    1. Not 100% sure, but do you get ‘Marie’ biscuits? Digestives are pretty sweet, crumbly biscuits.

    2. It’s a semi sweet biscuit made in Scotland. You might get them in Walmart it’s mcvities Digestive biscuit here look on web

  4. 5 stars
    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!!!!

  5. 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

  6. 5 stars
    Butternut cookies or ‘Nice biscuits’ can be used if you can’t find digestive biscuits for the base.

  7. 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!

    1. Ooh the orange sounds super cool I made one with pink icing, strawberry flavour and freeze dried strawberries on top – bliss

  8. 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!

  9. 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

  10. 5 stars
    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.

  11. 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

  12. 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

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Hello, I’m Amy, the voice-behind and creator-of Baking with Granny.

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