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birds-eye view of Mars Bar Squares and Mars Bars
15Prep Time

Mars Bar Cakes

Quick and easy

54 Reviews

About the bake

The humble Mars Bar Slice is definitely a retro childhood favourite and a fantastic rainy day bake to make with the family (no matter what their age). A chewy gooey cereal base blended with melted Mars Bars and topped with milk chocolate and white chocolate swirls - what's not to love?

Find out below how to make mars bar squares. 

15Prep Time


  1. Step 1:

    Prepare a 20cm square baking tin, by lightly greasing it and lining it with baking paper.

  2. Step 2:

    In a heatproof bowl, heat the butter, golden syrup and 3 of the chopped Mars Bars until they have melted. Don't worry if the Mars Bars do not full melt at this point. 

  3. Step 3:

    Add the Rice Krispies into the bowl and stir in with the remaining Mars Bar.

  4. Step 4:

    Pour the mixture into the baking tin and press down firmly (we used a potato masher for this)

  5. Step 5:

    In another heatproof bowl, melt the milk chocolate, stirring until smooth, then pour over the top of the Krispie mixture. 

  6. Step 6:

    Moving quickly before the milk chocolate sets, melt the white chocolate and drizzle in lines up and down the surface of the Mars Bar slice. Using a skewer, drag forward and back through the mixture to create a feathered effect.

  7. Step 7:

    Place the baking tin in the fridge to chill and set. Remove a little while before you plan to serve so that it is easier to cut into squares.


    • 100g Butter (unsalted, softened)
    • 4 Mars bars (chopped)
    • 1 1/2 tbsp Silver spoon golden syrup
    • 150g Rice krispies
    • 350g Milk chocolate
    • 50g White chocolate


  • 20cm square baking tin
  • Parchment paper

Nutritional Information

per 50g
  • 262cal Energy
  • 15g Fat
  • 8.7g of which Saturates
  • 29g Carbohydrates
  • 22g of which Sugars
  • 2.9g Protein
  • 0.21g Salt

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