Lemon Crumble Slice

I absolutely love this recipe for Lemon Crumble Slice. It’s by far one of my favourites (and that’s really saying something, given my addiction to all things involving sugar). I love this slice because not only does it have the yummiest oaty layers, but it seriously has the most amazingly creamy and delicious lemon filling. Creamy + lemony + oaty = all kinds of awesome.

Thermobliss Lemon Crumble Slice

The Thermomix really does make this lovely little recipe so simple. There’s really not much to it. Once you’ve made the oat layers, you whip up a simple lemon filling. No mess, no hassle. Gosh it’s recipes like this that really make me love my Thermomix. A LOT!!

Lemon Crumble Bars 1

So what are you waiting for? If you’re a fan of lemon flavoured desserts and slices, then you really, really must make this. You’ll love it – I pinky promise!!!

Lemon Crumble Bars 5

Lemon Crumble Slice

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  • cups (155g) plain flour
  • cups (110g) rolled oats
  • ½ tsp salt
  • ½ tsp bi-carb soda
  • ½ cup (100g) raw sugar
  • ½ cup (80g) packed brown sugar
  • ¾ cup (170g) unsalted butter, melted
  • 1 tsp vanilla extract
  • 1 X 395g can sweetened condensed milk
  • 1 tbsp finely grated lemon zest (approximately 1 lemon)
  • cup fresh lemon juice
  • 2 large egg yolks
  • ½ tsp lemon extract


  • Thermomix Instructions:
  • Preheat oven to 170 degrees celsius (160 degrees if fan forced)
  • Grease and line a 17X28cm slice tray with baking paper, allowing the edges to overhang.
  • Melt the butter and vanilla in the TM bowl for 40 seconds, Speed 2, 50 degrees.
  • Scrape down the sides of the bowl.
  • Melt for a further 1 minute, Speed 2, 50 degrees.
  • Add the plain flour, rolled oats, salt, bi-carb soda, brown sugar and raw sugar.
  • Mix for 20 seconds on Reverse, Speed 2.
  • Scrape down the sides.
  • Mix for a further 20 seconds on Reverse, Speed 2.
  • Spread half of the crumb mixture into the bottom of the prepared tray and press firmly into an even layer.
  • Bake in preheated oven for 15 minutes or until lightly golden.
  • Remove from oven and put aside (leave the oven turned on).
  • Place the zest of 1 lemon into the TM bowl.
  • Grate for 20 seconds on Speed 6.
  • Scrape the sides of the bowl.
  • Repeat steps 13-14 until you have a very finely grated zest.
  • Add the condensed milk, lemon juice, egg yolks and lemon extract and mix for 30 seconds, Speed 4.
  • Scrape the sides of the bowl and mix for a further 30 seconds, Speed 4.
  • Pour mixture over crumb crust in baking dish and spread into an even layer.
  • Sprinkle the remaining crumble mixture over the top of the lemon layer.
  • Bake in oven for 23 – 26 minutes or until lightly golden.
  • Remove from oven and allow to cool.
  • Cover and refrigerate for at least 2 hours (preferably overnight) then take it out and cut into squares.
  • Store in airtight container in refrigerator.


Comments 14

  1. ok so I’m confused, at number 11 you say to spread half of the crumb mixture into the tray, are we then supposed to side aside the other half? or do we leave it in there & zest the lemon on top of it? The instructions aren’t clear.

    1. Post

      Yes you set the second half of the crumble mixture aside (as that is what you crumble over the top). The lemon zest forms part of the middle (the creamy portion).

    1. Post

      Hi Tammy, I’m not sure as this is the only way I’ve made it. You could try experimenting though!!

    1. Post

      I personally dont like to freeze this slice as I have found that the filling can go a bit runny when defrosted. That being said, I know other people who are happy freezing it!! xx

    1. Post

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