The Best Peanut Butter Flapjack Recipe

Peanut butter for peanut flapjack recipe

Flapjacks are a traditional British sweet treat typically made from sugar, butter, porridge oats and golden syrup, baked in a flat oven tin and cut into tasty oaty bites.

Flapjacks became popular in the 1920s and have remained a staple snack ever since and we can see why! We’re sharing a delicious recipe for peanut butter flapjacks that will make a great breakfast on the go, a filling snack or an after-meal treat perfect for the kids.  

These peanut butter flapjacks are bursting with energy-boosting oats, full of iron, zinc, vitamin B and with the addition of peanut butter they provide a great source of protein essential for growing kids.  With endless variations, which we’ll get into later, you can have a play around and find your favourite combination. The best part? You don’t need to be a culinary expert to make them. These little beauties are incredibly simple to make, and you can whip them up in less than 30 minutes! So, what are you waiting for?

Peanut Butter Flapjack Recipe Ingredients


This peanut butter flapjack recipe will make approximately 20 oaty bars.

You will need:

300g Butter or margarine

200g Demerara sugar

100g Golden syrup

100g Crunchy peanut butter

450g Rolled oats

1tsp Vanilla extract

Icing sugar for dusting


Follow this simple guide to baking the best peanut butter flapjacks.

Step 1. Start by pre-heating the oven to 190°C and grease and line a 30x20cm baking tin with baking paper.

Step 2. In a large pan melt the butter over low heat.  Once it’s melted stir in the sugar, golden syrup and peanut butter and gently stir the ingredients over low heat until you have a smooth consistency.

Step 3. Remove the pan from the heat and pour in the porridge oats and vanilla extract.  Stir your ingredients until they have all combined and then spoon the mixture into your prepared cake tin.  Using the back of a spoon, press the mixture down firmly and evenly into the cake tin.

Step 4. Pop your cake tin into the oven and bake for 25 minutes until lightly golden on top.  Remove from the oven and allow to cool in the tin for 10 minutes.  Using a sharp knife, mark out 20 flapjack squares then allow to cool completely in the tin before removing.

Step 5. Your peanut butter flapjacks are ready to be served with a dusting of icing sugar. Enjoy!

Peanut butter flapjacks

Our Top Tips For The Perfect Flapjacks

If you want a crunchier flapjack then use a larger, shallower baking tin and turn up the oven by 20°C  and cook for approximately 10 extra minutes.

For a chewier flapjack try reducing the baking time a little. It may still be soft in the middle when you take it out of the oven but it will continue to set whilst it’s cooling.

Keep a close eye on your flapjacks during the final minutes of baking time and take out of the oven when they start to turn golden to prevent overcooking- nobody wants a burnt flapjack!

Want to make it vegan or dairy-free? This is a super easy recipe to make suitable for vegans as the only non-vegan ingredient in this recipe is the butter, so simply swap it out for vegan butter or dairy-free margarine.

Your flapjacks will keep for up to a week in an airtight container.

Tasty Extras

Want to spice up your flapjacks? Try adding in some of these goodies.

Dried fruits - these make a lovely addition and add in some extra goodness.

Chocolate Chips - for when you need an extra chocolatey boost!

Mashed banana - add these in for some added natural sweetness.

Flax seeds, pumpkin and sunflower seeds - a great way to sneak in some extra healthy fats!

Chopped nuts - add a great depth of flavour and some extra crunch!

Orange zest - a delicious addition, especially if you are adding in chocolate! Chocolate orange flapjacks- yum!

Chocolate raisins - why just add raisins when you can have chocolate covered raisins?

Cinnamon- adds extra depth and warmth to the flavour.

Honey - try replacing the golden syrup with honey for a sweeter flapjack.

Desiccated coconut -if you are a fan of coconut then you’ll love a sprinkle of this in your flapjacks!


Written By

Sarah Nyamekye

An outdoor pursuits person at heart, raised in the East Midlands countryside, Sarah now lives in Surrey with her two daughters aged 3 and 9. She loves to travel and spend her days outdoors finding new and exciting places to explore with her girls. If she’s not outdoors then you’ll likely find her at home baking, crafting, gardening as well as exercising to keep fit.

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