Lemon Jelly Slice

Name: Lemon Jelly Slice
Prep time: 20 min
Yield: approximately 16
Cuisine: Australian

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roubashahin.com.au

Desserts

Three layers, no oven, and twenty-five years in the making. This lemon jelly slice is pure nostalgia.

PREP TIME

20 minutes

COOK TIME

Chill Time

3 to 4 hours (overnight is best)

SERVES

approximately 16

About this recipe

There is something that has always been true about me, even before I had a food platform or a name for what I do. Whenever someone tasted something they loved, they would come to me. Not to talk about it — to recreate it. My sister was no different. She came home from school pick-up one afternoon and told me about a slice another mum had brought in. She could not stop talking about it. She went and got the recipe, came back and handed it to me — and that was that. I stuck it in my cookbook and life moved on.

That was over twenty-five years ago. When I found it again recently, I thought: it is time. This lemon jelly slice is exactly what it sounds like — a simple, no- bake dessert made with three honest layers: a buttery crushed biscuit base, a creamy condensed milk and lemon set in the middle, and a bright jelly layer on top. No oven, no fuss, no complicated technique. Just a recipe that has clearly earned its place.

What’s more, this lemon jelly slice is the kind of thing that suits almost any occasion. It is easy enough for a weeknight and pretty enough for a party. If you love simple no-bake slices, my Biscoff Banana Cheesecake Slice is another crowd-pleaser worth bookmarking — it has a similar ease but with a richer, creamier filling. And if you want something with a bit more old- fashioned character, my Marshmallow Pineapple Slice is as retro and beautiful as they come. This one, though, is all about the lemon. Sharp, bright, and set just right.

Ingredients

250 grams plain vanilla biscuits, finely crushed
175 grams unsalted butter, melted
¾ cup boiling water
2 teaspoons gelatine powder
395 grams condensed milk (1 standard tin)
¾ cup freshly squeezed lemon juice (approximately 3 lemons)
1 packet (85 grams) raspberry jelly crystals — or your preferred flavour
water for the jelly, as per packet instructions

Notes from Rouba

I used raspberry jelly for that beautiful pop of colour on top — but any flavour works. Lemon jelly doubles down on the citrus, strawberry is classic, and mango is a fun summer twist.
You do not need to grease the Pyrex dish, but you can if you like — it makes lifting the first slice out a little easier.
The bigger the dish you use, the thinner the layers will be. A 30 x 18 cm dish gives a nice height. If you use a larger tray, the slice will be flatter — which is fine, but worth knowing before you start.
Let the condensed milk layer set properly before adding the jelly. Give it at least 45 minutes to an hour in the fridge. If the jelly goes on too soon, it will sink through.
When you pour the jelly over the set condensed milk layer, use a spoon to spread it gently rather than pouring it directly. This keeps the layer beneath intact and the surface smooth.
Make this the day before if you can. It sets beautifully overnight and slices much more cleanly when fully chilled.
I mix the crushed biscuits and butter directly in the dish rather than in a separate bowl. Less washing up and it works just as well.

WHAT I USED

For this recipe I used a rectangular Pyrex dish — having a good, sturdy glass dish makes a real difference when you are working with set layers like these. You can find what I use in my kitchen over in my Amazon Shop here

Method

Step 1. Prepare the Base

Combine the crushed biscuits with the melted butter and mix until the crumbs are evenly coated. Press the mixture firmly into the base of a 30 x 18 cm Pyrex or baking dish, making sure it is packed in an even, compact layer. Place in the fridge while you prepare the filling.

Step 2. Make the Condensed Milk Layer

Pour the boiling water into a bowl and sprinkle over the gelatine powder. Stir well until the gelatine has completely dissolved with no lumps remaining. Add the condensed milk and the lemon juice and stir until the mixture is smooth and fully combined. Pour the filling over the chilled biscuit base and return the dish to the fridge. Allow it to set for at least 45 minutes to 1 hour, or until the layer is firm to the touch.

Step 3. Set the Jelly Layer

Prepare the jelly according to the packet instructions. Once the condensed milk layer is firm, use a large spoon to carefully pour the cooled jelly over the back of the spoon and onto the surface, moving it slowly and evenly across the dish. This prevents the jelly from breaking through the set layer beneath. Return the dish to the fridge and allow to set completely for a minimum of 4 hours, or overnight for best results.

Can I use any flavour of jelly?
Absolutely. Raspberry gives a beautiful pop of colour and a slightly tart contrast to the creamy lemon layer, which is why I love it. Strawberry, lemon, and mango all work well too. Go with whatever you have or whatever suits the occasion.

Do I need to grease the dish?
It is not essential, but a light spray or wipe of butter or oil along the base and sides will make it easier to lift out the first slice or two. Once you get going, it comes out cleanly on its own.

How do I know when the condensed milk layer is ready for the jelly?
Give it a gentle nudge — it should be firm and not at all wobbly. If it still has any movement in the centre, give it another 15 minutes. The jelly going on too early is the most common reason for the layers mixing, so it is worth being patient here.

Can I make this ahead of time?
Yes, and I would actually recommend it. This slice sets and slices beautifully when made the day before. Store it covered in the fridge and it will keep well for up to three days.

What size dish should I use?
I use a 30 x 18 cm Pyrex dish, which gives a good height to the layers. If you use a larger dish the layers will be thinner and flatter — the slice will still taste the same but will look quite different. A smaller, deeper dish will give you thicker, more generous layers.

Can I use orange juice instead of lemon juice?
You could — I actually thought about doing this myself before deciding to keep the original recipe as it was. Orange juice gives a softer, sweeter citrus flavour and would work well with the condensed milk layer. It's a lovely variation if you want to mix it up.

What type of biscuits should I use?
Any plain biscuit works here — Marie, milk arrowroot, digestives, Nice biscuits. You just want something simple without a strong flavour so it doesn't compete with the lemon layer.

How do I get clean slices?
The trick is a sharp knife dipped in hot water. Dip it, wipe it dry, then slice — and repeat between each cut. It glides straight through the jelly and condensed milk layers without dragging or cracking. It makes such a difference to how the slice looks on the plate.