This fun and colourful slice is as delicious as it looks, with a buttery biscuit base, lemon and condensed milk filling and – of course – the sweet jelly topping.
Best of all, it’s so easy to make. Below, I’ve broken the process into five easy steps. The recipe card at the very end of the post also includes all of the exact quantities and directions.
I’ve used raspberry jelly here but you can use your preferred jelly flavour to make this easy Jelly Slice.
Step 1: Prepare your jelly topping
Before you do anything else, make up the jelly topping.
Using your favourite flavour of jelly crystals (mine is raspberry for both the colour and flavour), add 1 cup of boiling water, as per the instructions on the packaging. Once you’ve stirred this well, add just 150ml of cold water and stir to completely dissolve the jelly crystals. Note that this is 50ml less than the packet instructs. By adding less water, this will ensure a nice, firm jelly topping that holds together when you cut your slice up into squares.
I’ve used Aeroplane jelly in this recipe. If you’re using a different brand of jelly, which may have slightly different instructions, just apply the same principle when making it up. Add a little less water for firmer jelly.
Once you’ve made up the jelly, set it aside so that it can cool to room temperature. Don’t place it in the fridge – we’re aiming for room temperature.
Step 2: Create the biscuit base
Now it’s time to create the base for our slice.
First, though, grease a slice tin (27 x 17cm) and line the base of it with two layers of baking paper. Allow the baking paper to overhang each side. This will help you to remove the slice from the tin once it’s set and you’re ready to slice it up.
Choose your favourite plain biscuits – I’ve used half a packet of Arrowroots and half a packet of Nice here – and chop them into a breadcrumb texture.
You can use a rolling pin, food processor or food chopper.
(I received this absolutely handy cordless KitchenAid Cordless Chopper for my birthday and love it!)
Melt the butter in the microwave or on a stovetop and then combine with the biscuit crumbs.
Press the biscuit mixture into the slice tin and then place it into the fridge to set while you move on to the next step.
Step 3: Mix up the middle layer
Okay, so this step just involves mixing all of the ingredients together until they’re well combined and the mixture is smooth:
- tin of condensed milk
- juice of two lemons (1/2 cup)
- 2 teaspoons of gelatine mixed with 1/2 cup of boiling water.
Once you have a beautiful smooth and creamy filling mixture, remove the slice tin from the fridge and pour over the filling mixture.
Return the slice to the fridge to set. You’ll need to leave it in the fridge for at least one hour.
Step 4: Get set
You can add the jelly layer once the jelly has reached room temperature and the filling layer has been in the fridge for at least an hour.
Before adding the jelly layer, I recommend placing the slice tin into a larger container. This will make it easier to transfer the slice to the fridge once the jelly layer has been added. The slice tin will also be quite full once you have added the jelly layer and the container can catch any spills (rather than your floor or fridge) if you get the wobbles transferring it to the fridge.
When pouring the jelly, there is a risk that the pour will dig little holes in your filling layer if the filling layer is still a little soft. To prevent this, use a spoon to disrupt the flow. So, pour the jelly slowly onto a spoon held above the slice tin and the pour will not be centred in one spot.
Once you transfer the slice, complete with jelly layer, back to the fridge you should leave it for at least six hours to set.
Step 5: And… go!
Ready? (Jelly) Set?
This slice looks so tempting that it will be hard to wait for it to set.
But please, do wait!
Once it’s set you can remove the slice from the tin using the overhanging baking paper to ease the whole slab of slice from the tin.
Occasionally, the baking paper might rip as you’re attempting this removal. If it does, don’t stress. Simply cut one row in the tin and remove piece by piece and then use a spatula to remove the remaining slab of slice.
Cut into 24 pieces using a sharp knife. The slice should keep in the fridge for up to five days.
And if you love this jelly recipe, you might like these other jelly recipes from the Cooking with Nana Ling collection:
- Jelly Lamingtons
- Jelly Crystal Cookies
- Flummery (Jelly Whip)
- Baked Mango Jelly Cheesecake
- Mini Trifles.
The original recipe
This jelly slice recipe is a popular one and various versions have been shared around for decades. I’ve based my recipe on one from a community cookbook, The Lourdes Hospital Recipe Book, 2nd Edition. This hospital is in Dubbo, NSW Australia and the original author is Ruth Ney. The cookbook is part of my mum’s collection.
I have, however, tweaked the original recipe a little and clarified the instructions. So please keep scrolling past the image of the original recipe below to the recipe card which is further below.
- 250 grams plain biscuits (Arrowroot, Nice, Marie or a combination of those work well)
- 185 grams butter, melted
- 395 gram tin of condensed milk
- 1/2 cup lemon juice (juice from approx 2 large lemons)
- 2 teaspoons gelatine powder
- 1/2 cup boiling water
- 85 gram packet jelly crystals (raspberry or another preferred flavour)
- 250 ml boiling water (1 cup)
- 150 ml cold water
- Prepare the jelly topping by mixing the jelly crystals with the boiling water and then cold water until crystals are dissolved. Note that we are making up the jelly using 50ml less water than the instructions on the package.
- Leave the jelly out so it cools to room temperature.
- Grease a slice tin (27 x 17cm) and line base with two layers of baking paper, allowing the baking paper to overhang each side (to assist with removal once it's ready to slice).
- Crush the biscuits until they resemble fine breadcrumbs using a rolling pin, chopper or food processor.
- Add melted butter to the biscuit crumbs and stir to combine.
- Press the biscuit mixture into the bottom of the slice tin and smooth with the back of a metal tablespoon. Place into fridge.
- Pour condensed milk into a bowl. Add the lemon juice and use a whisk to combine.
- Dissolve gelatine in the boiling water and then add this to the lemon and condensed milk mixture. Use the whisk to combine.
- Remove the slice tin from the fridge and pour over the filling mixture. Return to fridge for at least one hour to set.
- Once jelly has reached room temperature and filling has been in fridge for at least one hour, remove the slice tin from the fridge and place in a larger dish (this will make it easier to transfer to the fridge and catch any jelly spills).
- Pour the jelly over the second layer of the slice. (TIP: Pour onto a metal spoon to break up the flow and avoid the direct flow creating a hole in the filling layer of the slice).
- Return to the fridge and allow to set for at least 6 hours.
- Remove slice from tin using the overhanging baking paper to ease the whole slab of slice from the tin. (TIP: If this method doesn't work, cut one row in the tin and then use a spatula to remove the remaining slice.) Cut into 24 pieces using a sharp knife.