Thermomix WeetBix Slice

This Thermomix WeetBix Slice recipe is sure to be a hit with the whole family!

Thermomix Weetbix Slice Recipe

 This easy peasy Thermomix WeetBix Slice makes a great treat for the kids AND it’s also freezer friendly.  We’ve been making this slice quite a bit lately as my boys are just fascinated that their ‘breakfast’ is used to make this yummy slice!

Thermomix Weetbix Slice

I really enjoy making these classic recipes from my childhood with my kids, and love really love helping me make them too.  We keep it really simple when it comes to icing and decorating this Thermomix Weetbix Slice and stick with a simple chocolate icing (that the kids can make, with supervision of course) themselves and then of course we have to add 100s and 1000s!
Thermomix Weetbix Slice

When you are making this recipe, it’s important to make sure you allow the slice to completely cool before adding the icing, otherwise it will soak into the slice and you will end up with a bit of a mess. If you want to help the slice cool more quickly, try popping it into the fridge or freezer.

Thermomix Weetbix Slice

Thermomix WeetBix Slice

Our Thermomix WeetBix Slice is a family favourite! It's perfect for the kids lunchboxes too.
4.25 from 4 votes
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Prep Time: 10 minutes
Cook Time: 21 minutes
Total Time: 31 minutes


  • 12 WeetBix
  • 200 grams butter
  • 30 grams cocoa
  • 150 grams brown sugar
  • 30 grams desiccated coconut
  • 1 egg
  • 225 grams icing sugar for the chocolate icing
  • 1 tbsp cocoa for the chocolate icing
  • 1 tsp butter for the chocolate icing
  • 2 tbsp boiling water for the chocolate icing


  • Preheat your oven to 160 degrees and line an 18 x 28cm slice tray with baking paper.
  • Place the weetbix into your Thermomix bowl and blitz for 10 seconds on speed 7 to crush. Transfer the crushed weetbix to another bowl and set aside until needed.
  • Without washing the bowl, place the butter into your Thermomix bowl and cook for 3 minutes, 60 degrees, speed 2 to melt.
  • Add the crushed weetbix, cocoa, brown sugar, coconut and egg to your Thermomix bowl and mix for 10 seconds speed 4. Scrape down the sides of your bowl and mix for a further 10 seconds, speed 4.
  • Transfer the mixture to your prepared slice tray and cook for 18 - 20 minutes, you want the slice to be firm to the touch.
  • Allow the Weetbix Slice to completely cool in the tin before preparing the icing. Combine all of the icing ingredients into a bowl and mix until smooth and combined.
  • Pour the icing over the completely cooled slice and use a butter knife to smooth. Decorate if desired
  • Once the icing has set, cut the slice into pieces and enjoy!


Make sure you let the Weetbix Slice completely cool before adding the icing.
This slice will keep for up to one week in an airtight container.

For more yummy slice recipes, make sure you check out our popular ‘Thermomix No Bake Slices and Bars‘ eBook.

You can shop all of our ebooks and printed books here.

Thermomix No Bake Slices and Bars eBook

Comments 1

  1. Hello
    I’ve just made the weetbix slice and it is very buttery. Should the recipe have any flour in it.
    Thanks for your help. 😄

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