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    Home » Recipes » Traybakes

    Published on May 20, 2017. Modified on Jun 20, 2025 by bakingqueen74. This post may contain affiliate links. 32 Comments

    Rhubarb Flapjacks (Oat Bars)

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    • 36
    Jump to Recipe

    Rhubarb flapjacks are great for after-school snacks and treats. Flapjacks always go down well and a bit of added fruit is ideal!

    Rhubarb flapjacks (oat bars)

    Having picked this rhubarb up at the fruit and vegetable market in Kingston, the same place my mum used to shop when I was a child, I decided to use it in a bake for the family.

    Jump to:
    • Ingredients
    • Instructions
    • Recipe
    • Reviews

    Ah rhubarb, bringing back childhood memories of rhubarb crumble and stewed rhubarb with custard.

    Growing it on our allotment, it was a frequent sight on the table!

    Did you know that flapjacks mean something different depending on where you live?

    These are of course the British flapjacks which are delicious oat bars made with sugar, butter and golden syrup.

    A traditional chewy flapjack with those lovely crispy bits around the edge, the layer of cooked rhubarb adds colour, flavour and softness.

    A bit like rhubarb crumble in slice form!

    Ingredients

    Here’s what you will need for this recipe – quantities are in the recipe card further down:

    • rhubarb
    • granulated sugar
    • oats
    • muscovado sugar
    • golden syrup
    • butter
    • vanilla extract

    Instructions

    As an overview of the recipe, you will cook down the rhubarb until it has softened but still has some chunks.

    Then spread it over two thirds of the oat mixture before adding the rest of the oat mixture on top.

    Here are the step by step instructions:

    1. Place the rhubarb and granulated sugar in a saucepan with a splash of water. Cook gently for 5-10 minutes until the rhubarb softens but some of the chunks are still visible.
    2. Put the muscovado sugar, golden syrup, vanilla extract and butter in a large bowl and melt in the microwave. This took 2 minutes in my microwave until fully melted.
    3. Place the oats in another bowl and pour the butter and sugar mixture over it. Combine well. 
    4. Line a square baking tin with baking paper and then spread two thirds of the oat mixture into the base of it. Press down well.
    5. Spread the cooled rhubarb mixture over the oats and then place the remaining third of the oat mixture over the top, again pressing down well.
    6. Bake at 180℃ / 350℉ for 35 minutes, until golden on top.
    7. Remove from the oven and allow to cool. The flapjacks will harden as they cool so cut into nine pieces while warm, leave to cool in the tray, and then remove and pull apart once cold.
    Rhubarb flapjacks (oat bars)

    Once baked I could hardly keep my fingers off these, the smell of rhubarb and that golden crust from the golden syrup!

    Rhubarb flapjacks (oat bars)

    Lovely warm from the pan (add ice cream for indulgence) or cold, and great in a lunchbox.

    Rhubarb flapjacks (oat bars)

    Little fingers couldn’t keep away from these, I was glad to have spread my love of rhubarb a bit further.

    Rhubarb flapjacks (oat bars)

    Variations

    If you aren’t a fan of rhubarb, try my strawberry flapjacks or apricot flapjacks instead!

    Pin these rhubarb flapjacks for later

    Rhubarb flapjacks (oat bars)

    Recipe

    Flapjack with chunks of rhubarb on wooden board.

    Rhubarb flapjacks (oat bars)

    A tasty seasonal bake using rhubarb in chewy flapjacks
    4.95 from 18 votes
    Print Pin Rate Save Saved!
    Course: Baking
    Cuisine: British
    Prep Time: 10 minutes minutes
    Cook Time: 35 minutes minutes
    Total Time: 45 minutes minutes
    Servings: 9
    Calories: 308kcal
    Author: Lucy Allen | BakingQueen74

    Ingredients

    • 300 g rhubarb chopped
    • 50 g granulated sugar
    • 250 g rolled oats
    • 100 g muscovado sugar
    • 4 tbsp golden syrup
    • 125 g butter
    • 1 tsp vanilla extract
    UK Measurements – US Measurements

    Equipment

    mixing bowl
    mixing bowl
    spatula
    spatula
    9x9 silicone
    9×9 silicone

    Instructions 

    • Place the rhubarb and granulated sugar in a saucepan with a splash of water. Cook gently for 5-10 minutes until the rhubarb softens but some of the chunks are still visible.
      300 g rhubarb, 50 g granulated sugar
    • Put the muscovado sugar, golden syrup, vanilla extract and butter in a large bowl and melt in the microwave. This took 2 minutes in my microwave until fully melted.
      100 g muscovado sugar, 4 tbsp golden syrup, 1 tsp vanilla extract, 125 g butter
    • Place the oats in another bowl and pour the butter and sugar mixture over it. Conbine well. 
      250 g rolled oats
    • Line a square baking tin with baking paper and then spread two thirds of the oat mixture into the base of it. Press down well.
    • Spread the cooled rhubarb mixture over the oats and then place the remaining third of the oat mixture over the top, again pressing down well.
    • Bake at 180℃ / 350℉ for 35 minutes, until golden on top.
    • Remove from the oven and allow to cool. The flapjacks will harden as they cool so cut into nine pieces while warm, leave to cool in the tray, and then remove and pull apart once cold.
    Did you try and love this recipe?Then please leave a star rating and comment below to let me know how you got on!

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    Reader Interactions

    Comments

    1. Colleen says

      June 22, 2025 at 10:45 pm

      I harvested my rhubarb in BC Canada today and made these rhubarb flapjacks. They turned out absolutely wonderful and so tasty. I will definitely be making these again.
      I also made your chocolate chip flapjacks too, but used whole bar 85% plain chocolate as that is my husband’s favorite. The combination of sweetness and dark chocolate was amazing. I may not get to try another one, my husband’s appreciation of them means that they won’t last long enough to freeze the surplus.
      Thank you for posting such amazing recipes that are so easy to follow along with

      Reply
      • bakingqueen74 says

        June 24, 2025 at 8:09 pm

        Hi Colleen, I am so glad to hear this! I visited BC about 20 years ago and thought it wad a beautiful place. Awesome to hear you like my recipes, this is fab.

        Reply
    2. Sally Wilson says

      April 26, 2025 at 4:18 pm

      Made these yesterday with home grown rhubarb, wow the blend of the sharp rhubarb with the sweet flapjack mix is divine…. a new winner to share with my friends.

      Reply
      • bakingqueen74 says

        April 26, 2025 at 4:42 pm

        So glad to hear this Sally, thanks very much for leaving your review. Jealous of your home grown rhubarb!

        Reply
    3. Kim says

      May 21, 2024 at 7:54 pm

      I made these today, absolutely delicious! Thank you!

      Reply
      • bakingqueen74 says

        May 21, 2024 at 8:27 pm

        That’s wonderful Kim, I am so glad you enjoyed them! I am making a batch tomorrow since it is rhubarb season!

        Reply
    4. Celia says

      June 17, 2023 at 8:41 pm

      These are soooooo good! I reduce the sugar by a sprinkle just for my taste, add crystalized ginger to the rhubarb and ground ginger to the oats for an extra kick.
      But these are utterly delicious. : )
      Did a batch and a half for the guys at work and they were devoured! Thanks for the recipe

      Reply
      • bakingqueen74 says

        June 25, 2023 at 8:14 am

        Brilliant, so glad to hear! The extra ginger sounds fab too.

        Reply
    5. Mary says

      May 14, 2023 at 5:13 pm

      Loved these made them today ……can i freeze these flapjacks

      Reply
      • bakingqueen74 says

        May 15, 2023 at 5:24 pm

        Great! Yes you can freeze them wrapped tightly in baking paper and clingfilm. I normally freeze them for a maximum of a month.

        Reply
    6. Ann Traynor says

      July 30, 2021 at 8:32 pm

      Just picked some rhubarb from my garden. Going to try your recipe tomorrow. Flapjack & rhubarb 2 of my favourite things.

      Reply
    7. Amanda says

      April 30, 2020 at 9:08 am

      These are amazing. I added ginger to my homegrown rhubarb

      Reply
      • bakingqueen74 says

        April 30, 2020 at 12:53 pm

        Yum that sounds so good!

        Reply
    8. Saffron says

      April 19, 2020 at 12:51 pm

      Bloomin’ ek! This is a total winner made a couple of times now with fresh rhubarb from our allotment. Nice easy recipe for the boys to make

      Reply
      • bakingqueen74 says

        April 19, 2020 at 3:21 pm

        Excellent so glad you enjoyed it! Jealous of fresh rhubarb from allotment too.

        Reply
    9. Clair Dyer says

      April 14, 2020 at 8:54 am

      These are AMAZING!!! Thank you for this delicious recipe!!!!

      Reply
      • bakingqueen74 says

        April 14, 2020 at 12:35 pm

        So glad you enjoyed it! I wish I had some rhubarb now

        Reply
      • Dunkie says

        June 12, 2021 at 8:48 am

        Great recipe and so quick to make! I added pecans, macadamias and peanut butter chips too which worked nicely.

        Reply
        • bakingqueen74 says

          June 22, 2021 at 11:16 am

          Excellent, thanks for leaving a review. The nuts sound like a tasty addition!

          Reply
    10. Janice Pattie says

      March 23, 2020 at 7:54 pm

      What a great idea, I’m definitely going to make these.

      Reply
      • bakingqueen74 says

        March 23, 2020 at 9:02 pm

        Thanks Janice you grow your own rhubarb don’t you

        Reply
    11. ndemi says

      June 09, 2017 at 9:09 am

      Will try this recipe over the weekend.

      Reply
    12. Kat (The Baking Explorer) says

      June 06, 2017 at 10:13 pm

      Such a fab idea to add rhubarb to flapjacks!

      Reply
    13. Jo @ Jo\'s Kitchen Larder says

      May 23, 2017 at 7:50 pm

      These look soo good and as I am now newly converted rhubarb fan, I will have to give them a go 🙂 I have only ever baked flapjacks with plums and they were delicious so I can only imagine how lovely these are. 🙂

      Reply
      • bakingqueen74 says

        May 23, 2017 at 8:36 pm

        I can’t believe anyone could not have liked rhubarb before! 😀

        Reply
      • Clair Dyer says

        April 14, 2020 at 8:57 am

        Ohhhh plums! Not used them before- definitely going to try that! THese rhubabrb ones are absolutely delicious and so gooey! Making more today, but used up all my garden rhubarb, so using some bananas that are over ripe!

        Reply
    14. Jen says

      May 23, 2017 at 4:29 pm

      I love flapjacks but have never added rhubarb to them before. Will definitely be trying it this summer!

      Reply
      • bakingqueen74 says

        May 23, 2017 at 8:33 pm

        Fab! Love the ginger you added

        Reply
    15. Ren Behan says

      May 22, 2017 at 3:15 pm

      Great use of seasonal rhubarb and a lovely pairing of sweet and sour.

      Reply
      • bakingqueen74 says

        May 23, 2017 at 8:33 pm

        Thanks Ren, I didn’t think of the sweet and sour!

        Reply
    16. Choclette says

      May 22, 2017 at 8:56 am

      Now why have I never thought of adding rhubarb to flapjacks? I love flapjacks and I love rhubarb. Brilliant idea Lucy, your flapjacks sound ace 🙂

      Reply
      • bakingqueen74 says

        May 23, 2017 at 8:16 pm

        Thanks Choclette it turned out to be a great combination!

        Reply
    4.95 from 18 votes (10 ratings without comment)

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    Hi, I'm Lucy! I'm a slow cooker addict, food blogger and also a busy working mum of two. I hope you'll enjoy the recipes I create and post which are perfect for busy families.

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