These peanut butter flapjacks are a beautiful afternoon treat. Sweet and rich, with a little saltiness from the peanut butter, you can make these flapjacks either soft and gooey or firm and crunchy, based on your preference.
If you’re scratching your head thinking that the picture looks nothing like a flapjack you’ve ever had, that’s because this recipe is for British flapjacks which are an oaty-baked treat rather than sweet American pancakes.
Is peanut butter good for you?
Despite being ridiculously tasty and moreish, peanut butter does have several health benefits. Firstly, it’s high in protein and will help keep you satiated for longer, since it’s low in sugar and high in slow-release energy fats.
While it does have a fairly high-fat content, the majority of fats found in the butter are unsaturated so they can help reduce cholesterol. It’s also quite high in fibre which can help reduce your risk of heart disease and diabetes.
However, peanut butter does contain a high proportion of fat and calories, coupled with the fact that flapjacks are loaded with sugar and syrup. Moderation is key!
Why is my flapjack crunchy?
If your flapjacks are coming out too crunchy for your liking, then the most likely reason is that you have baked them for too long in the oven. When you remove the flapjacks from the oven, they will still be soft and will harden more as they cool. So don’t be tempted to keep baking them until they are fully firm.
Rough cooking times for flapjacks are 20-30 minutes for soft and chewy, 30-40 minutes for medium-soft and 50 minutes for crunchy and firm. (Naturally, factors like the size of your baking dish, the size of the batch you are making, and your oven temperature will affect this).
You might also have overdone the butter, sugar, syrup and peanut butter in the first couple of recipe steps if your flapjacks are too hard. This reduces the mixture to more of a caramel. You only need to melt the ingredients in this step, not simmer or boil them.
How do you stop them from falling apart?
The main culprit for flapjacks that fall apart or disintegrate is cutting them before they have fully cooled. If you are impatient and want to dig into your prized treats as quickly as possible then leave them on the counter until slightly warm and then transfer them to the fridge to fully cool.
It is also important to press the mixture down firmly before placing them in the oven. This will help to press out any air and help everything stick together.
How long do they keep?
These flapjacks can be kept at room temperature in an air-tight container or tin for around a week. I recommend adding a layer of baking/parchment paper inside the tin to line it.
You can also freeze the flapjacks for up to 3 months. Stack them in a sealed container or pop them into a food bag before freezing. If you are stacking them then place a piece of parchment/baking paper between each layer to stop them from sticking together.
For a full list of ingredients with weights and measurements jump to the printable recipe card.
- Unsalted butter
- Soft light brown sugar
- Crunchy peanut butter – you can substitute for smooth for a more uniform texture
- Golden syrup – If you can’t get golden syrup where you live then you can substitute for honey or light corn syrup. However, corn syrup is thinner so you might want to use slightly less to stop the mixture from becoming too runny.
- Sea salt
- Rolled porridge oats
Baking dish – around 20cm x 12cm / 8in x 4.5in for 6 portions (the default recipe). This one from Amazon is a great size
How to make them
For more detailed steps with recipe tips jump to the printable recipe card.
- Preheat the oven to 150C/300F.
- Melt the butter, sugar, peanut butter and syrup in a large pan until fully melted. Stir in the sea salt.
- Tip the oats into the butter mixture and mix until fully coated.
- Line a baking tray with parchment/baking paper and spoon the mixture in. Use the back of a wooden spoon or spatula to press the mixture into the tray so it is even.
- Bake for 40 minutes (for a medium-soft flapjack).
- Leave the flapjacks to cool before cutting them in the tray and then transferring to a sealable container or tin.
Looking for more sweet treat recipes? Try:
- Dark chocolate flapjacks
- Yorkshire parkin
- Date and walnut cake
- Coffee and walnut cupcakes
- Individual yogurt cakes
Products that work well for this recipe:
Set of 3 Emma Bridgewater Cake Storage Tins
Small Ceramic Baking Dish
Beeswax Food Wraps
These peanut butter flapjacks are a beautiful afternoon treat. Sweet and rich, with a little saltiness from the peanut butter.
The default recipe makes 6 flapjacks
- 75g / 2.6oz unsalted butter
- 75g / 2.6oz soft light brown sugar
- 50g / 1.75oz crunchy peanut butter
- 2 tbsp golden syrup (see note 1)
- 1 pinch sea salt
- 175g / 6.1oz rolled porridge oats
- Baking dish – around 20cm x 12cm / 8in x 4.5in for 6 portions (the default recipe). This one from Amazon is a great size
- Preheat the oven to 150 C / 300F
- Place the butter, sugar, peanut butter, syrup and salt in a small saucepan over medium heat. Slowly heat until everything has melted together into a smooth even syrup.
- Add the oats to the pan and stir everything together until the oats are fully coated.
- Line a baking tray with baking/parchment paper and tip the oat mixture in. Use the back of a large spoon to evenly smooth the mixture across the tray and gently press down.
- Place in the oven for around 40 minutes, until golden brown (see note 2,3,4). Leave to cool before slicing.
- If you can’t get golden syrup where you live then you can substitute for honey or light corn syrup. However, corn syrup is thinner so you might want to use slightly less to stop the mixture from becoming too runny.
- Adjust the cooking time based on how firm you would like them. 40 minutes should give a medium-firm flapjack. Increase or decrease the time depending on how firm you like them. 30 minutes will give a chewier result and 50 minutes a crunchier flapjack.
- The size of baking tray you use will also affect the cooking time – depending on how thick or thin the layer of flapjack is.
- The flapjacks will continue to firm up as they cool so don’t worry if they seem slightly too soft when they come out of the oven.
- Keep the baked flapjacks in an airtight container at room temperature for up to 7 days.
- You can also freeze the flapjacks for up to 3 months. Stack them in a sealed container or pop them into a food bag before freezing. If you are stacking them then place a piece of parchment/baking paper between each layer to stop them from sticking together.
- Prep Time: 15 minutes
- Cook Time: 40 minutes
- Category: Snack
- Method: Bake
- Cuisine: British
- Serving Size: 1
- Calories: 320
- Fat: 17g
- Carbohydrates: 35g
- Protein: 5g
Keywords: snack, afternoon tea, sweet, biscuit, cookie, peanut butter, flapjack