This easy jam squares recipe is just like grandma used to make - nostalgically old-fashioned, buttery and packed with fruity jam!
With a shortbread crumble topping that's way more indulgent than oatmeal jam squares, this recipe is quick, easy and perfect for beginner bakers.
Whether you're making them for a bake sale or a cosy afternoon treat, these jam crumble slices are ever the crowd-pleaser.
We used strawberry jam, but feel free to pick your favourite!

Jump to:
- What's to love about this recipe
- You may also love ❤️
- Key ingredient notes and substitutions
- Baking pan size
- How to make jam squares: Step-by-step instructions
- Top tips for the best jam crumble bars
- Storage
- Can you freeze jam squares?
- How is this different to Hungarian Tart?
- Recipe
- Top tips for the best jam crumble bars
For more easy-bake or no-bake recipes, try these date balls, date squares or coconut ice with condensed milk.
What's to love about this recipe
- A nostalgic, old-fashioned favourite - just like grandma used to make!
- Buttery, rich shortbread crumble (no oats here!).
- Super easy - just 15 minutes of prep and 30 minutes in the oven.
- Totally customizable - swap in apricot, raspberry or your favourite jam.
- Perfect for beginner bakers!
You may also love ❤️
Key ingredient notes and substitutions
**Please see the recipe card at the bottom of this post for the full recipe and list of ingredients.
Butter
Use either salted or unsalted butter, softened. If using salted butter, you can omit the salt from the recipe, although it's not really necessary.
White granulated sugar
For the best texture, stick with good old white sugar for the crumble topping - brown sugar makes it too soft.
Jam
For these strawberry jam bars, we’re using strawberry jam (obviously!) but the beauty of homemade jam squares is that you can pick your favourite jam filling!
Try apricot jam squares, blueberry jam squares or even fig jam for a posh twist. Peach, plum and raspberry preserves also work wonderfully.
You can even get creative for special holidays:
- Think Christmas jam squares with a festive flavour like cranberry or spiced plum.
- Easter jam squares with bright, citrusy flavours.
- For a summer party, blueberry jam squares or peach jam squares are a great choice.
Coconut variation
For an extra layer of flavour and texture, try scattering some desiccated coconut over the crumble topping before baking.
It adds a delicious crunch and a hint of coconutty sweetness for a simple coconut jam square variation.
Baking pan size
For this classic jam squares recipe, you’ll need a 20cm x 20cm (8" x 8") square baking pan, lined with parchment paper to prevent sticking and make it easy to lift the squares out.
How to make jam squares: Step-by-step instructions
1. In a large bowl, beat the butter and sugar until light and fluffy. Use a stand mixer, hand mixer or food processor.
2. Add the egg and mix to combine.
3. In a separate medium bowl, combine the dry ingredients; All-purpose flour, baking powder and salt.
4. Add it to the butter mixture.
5. Work the mix together with your hands. Be patient as it's a very dry, stiff dough mixture, but it will come together.
6. Shape the dough into log. Wrap in cling film and chill in the fridge for at least 1 hour, or in the freezer for 30 minutes.
7. Preheat oven to 180°C/356°F/gas mark 4.
8. Line a 20cm x 20cm square pan with baking paper. Leave a slight overhang as it makes it easier to lift the jam bars out later.
9. Cut a ¾ piece from the log of dough and place the other ¼ back in the fridge for now.
10. Use the rough side of a cheese grater to grate the dough into crumbs.
11. Spread the crumbs evenly into the bottom of the prepared pan.
12. Briefly warm the jam in the microwave until it's slighter runnier and easier to spread.
13. Spoon the jam evenly across the crumb base.
14. Grate the remaining dough from the fridge and sprinkle it over the jam.
15. Bake the jam crumble bars for 25-30 minutes until lightly golden brown on top.
16. Allow the bake to cool completely in the tin before removing it and cutting it into 12 squares using a sharp knife. We like to let it rest in the fridge to firm up before slicing.
Top tips for the best jam crumble bars
Don’t add extra liquid to the dough
It might seem dry, but that’s normal for a shortbread texture! Don’t be tempted to add liquid - it will come together and give you the perfect short, buttery crumb.
Adjust the amount of jam if you wish
Use up to 500g (17.6 oz) of jam for a thicker layer of preserve, or opt for a bit less if you prefer a lighter filling.
Chill or freeze the dough for neat crumbs and the best texture
For uniform crumbs, chill or freeze the dough before grating it.
Roll it into a log, wrap it in cling film and refrigerate for at least an hour. If you’re having trouble grating it, pop it in the freezer for a few minutes to firm it up.
Warm your jam for easy spreading
Slightly warm the jam before spreading - it makes it way easier to get an even layer on your dough.
Cool before slicing
Allow your traditional jam squares to cool completely before slicing. We recommend popping the tin in the fridge for a while to get sharp, clean slices.
With these simple tips, you’ll get jam crumble bars that are perfectly shortbread-y-buttery, jam-filled and slice-ably-delicious!
Storage
These jam squares stay fresh for up to four days in an airtight container, and they’re at their absolute best on days two and three!
Can you freeze jam squares?
Yes, you can freeze jam squares for up to three months.
After baking and cooling, cut them into portions and freeze them on a parchment-lined baking sheet until firm. Transfer the frozen squares to an airtight container or freezer bags and label them with the date.
To enjoy later, thaw the squares at room temperature for about 30 minutes to an hour.
How is this different to Hungarian Tart?
It’s not - it’s the same thing! In South Africa, these delicious shortbread jam squares are called 'Krummel tert', while elsewhere they’re known as 'jam crumble bars' or 'jam slice'. It’s a classic treat with universal appeal!
Recipe
Easy Old-fashioned Jam Squares
Equipment
- 1 20cm x 20cm (8" x 8") square tin - lined with parchment paper
Ingredients
- 225 gram (8oz) unsalted butter - softened
- 140 gram (5oz) sugar
- 1 egg - room temperature
- 450 gram (16oz) plain flour
- 3 teaspoon baking powder
- ½ teaspoon salt - optional: you can omit the salt if using salted butter
- 450 gram (16oz) strawberry jam - or other jam of choice
Instructions
- Beat the butter and sugar until light and fluffy. You can use a stand mixer, hand mixer or a food processor.225 gram (8oz) unsalted butter, 140 gram (5oz) sugar
- Whisk the egg in a separate bowl and add it to the butter and sugar. Beat again until the egg is fully incorporated.1 egg
- In a separate bowl, mix the flour, baking powder and salt together.450 gram (16oz) plain flour, 3 teaspoon baking powder, ½ teaspoon salt
- Add the dry ingredients to the butter, sugar and egg mixture.
- Work the mix together with your hands. Be patient as it's a very dry mixture, but it will come together. The dough will be quite stiff.
- Shape the dough into log. Wrap in cling film and chill in the fridge for at least 1 hour, or in the freezer for 30 minutes.
- Pre-heat the oven to 180C/356F/gas mark 4.
- Line a 20cm x 20cm baking tin with baking paper. Leave a slight overhang as it makes it easier to lift the traybake out later.
- Cut a ¾ piece from the log of dough and place the other ¼ back in the fridge for now.
- Use the rough side of a cheese grater to grate the dough into coarse crumbs. It helps to do the grating on a very large plate or a large chopping board.
- Spread the crumbs evenly into the bottom of the baking dish.
- Briefly warm the jam in the microwave until it's slighter runnier and easier to spread.We find that 45 seconds to 1 minute usually does the trick, stopping halfway through to give it a stir.450 gram (16oz) strawberry jam
- Evenly spoon the jam over the crumb base.
- Grate the remaining quarter of dough with the cheese grater.
- Sprinkle the crumbs over the top of the jam.
- Bake for 25-30 minutes or until lightly golden brown on top.
- Allow the bake to cool completely in the tin before removing it. It's crucial not to lift the bake from the baking tin until it has completely cooled down. We like to speed up the process with a 10 minute blast (or longer) in the fridge.
- Use a sharp knife and cut into 12 squares or bars.
Notes
Top tips for the best jam crumble bars
Don’t add extra liquid to the dough
It might seem dry, but that’s normal for a shortbread texture! Don’t be tempted to add liquid - it will come together and give you the perfect short, buttery crumb.Adjust the amount of jam if you wish
Use up to 500g of jam for a thicker layer of preserve, or opt for a bit less if you prefer a lighter filling.Chill or freeze the dough for neat crumbs and the best texture
For uniform crumbs, chill or freeze the dough before grating it. Roll it into a log, wrap it in cling film and refrigerate for at least an hour. If you’re having trouble grating it, pop it in the freezer for a few minutes to firm it up.Warm your jam for easy spreading
Slightly warm the jam before spreading - it makes it way easier to get an even layer on your dough.Cool before slicing
Allow your traditional jam squares to cool completely before slicing. We recommend popping the tin in the fridge for a while to get sharp, clean slices. With these simple tips, you’ll get jam crumble bars that are perfectly shortbread-y-buttery, jam-filled and slice-ably-delicious!**Nutritional data disclaimer**
Please keep in mind that the nutritional information provided below is calculated by a third party and we cannot guarantee the accuracy. We try our best to give you the most accurate information, but we do not take responsibility for errors that may be present. Also, the nutritional value of the recipe may change depending on the exact brands and products used. We recommend that you consult with a qualified healthcare professional or registered dietitian for personalised advice on your dietary needs.
Nutrition
For food safety advice, including guidance on food allergies
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