Creamy, sweet and tangy Lemon Slice that you can make using only 5 ingredients! Extremely easy to make, this is a perfect first bake if you’re a beginner or just fancy a no-fuss dessert! This Easy Lemon Slice with condensed milk can be decorated with lemon zest or raspberries if you want to impress!
Have Leftover Condensed Milk?
After making my Easy Eggnog for the Christmas Lattes, I had half a tin of condensed milk to use and were looking for ideas. I normally make a key lime pie (Seb’s favourite recipe here) with condensed milk, but this time, I decided to use lemons. Only having half of a tin of condensed milk to spare, I used a loaf tin for this recipe instead of making a large round pie. I used a 2 lbs loaf tin for this recipe. But you can easily double the recipe. Just make sure you use a tin twice as big for the slices to be ready in the same amount of time.
What Does A 5-Ingredient Lemon Slice Taste Like?
I love citrus desserts, be it a classic Tart au Citron, Key Lime Pie or a Lemon Cheesecake. This simple 5 ingredient lemon bar has an element of each of the above, really. Creamy as cheesecake, tangy as Lemon Tart and has a lovely biscuit base just like our favourite key lime pie.

Ingredients and Substitutes
- oat biscuits: can be substituted with digestive biscuits or Graham Crackers.
- butter: you can use salted or unsalted in this recipe. I personally like salted butter to counterbalance the sweetness of condensed milk and the tart of the lemon in the filling.
- condensed milk: sweetened.
- lemon juice: from approx. 1.5 lemons for this recipe.
- eggs: medium in the UK, large in the US.
Method
STEP 1: Make The Biscuit Base
To make these Easy Lemon Slices, preheat the oven to 160°C Fan. Crush 100g of oat biscuits into fine crumbs. I simply put them in a large mixing bowl and bash them with the end of a rolling pin, but use a food processor if you have one (we love Kenwood) I then mix them with 50g of melted butter.


With the back of a tablespoon or a spatula, press the buttery biscuit mixture into a baking-parchment lined loaf tin/ baking tray (with a surface area of about 250cm²). Make sure to get the mixture into all four corners. Then pop in the oven to bake for 10 minutes.
STEP 2: Make the Lemon Slice Filling
In the meantime, using an electric whisk, beat the condensed milk, eggs and lemon juice in a large bowl. I’ve tried using freshly squeezed lemon juice and the juice from the bottle. The latter was more tart, but both worked really well. Beat the mixture for 2-3 minutes, until slightly increased in volume.
STEP 3: Bake and Decorate
When the base is baked, pour the lemon mixture on top and return to the oven for 15-20 minutes until the filling sets. Cool completely at room temperature, then chill in the fridge for at least 2 hours before cutting your lemon slice with condensed milk into bars.
If you wish, you can decorate with icing sugar, lemon zest or raspberries, or even pipe some dark chocolate on top.

How To Store 5-Ingredient Lemon Slices?
Keep the lemon slices in the fridge for up to 4 days. However, take them out of the fridge 15-30 minutes before serving as they taste better at room temperature. We find these slices don’t freeze very well.
Other Easy Dessert Recipes
If you’re looking for other easy desserts and bakes to make, have a look at the following:
Recipe Card

5-Ingredient Lemon Slice With Condensed Milk
Equipment
- Loaf Tin
Ingredients
- 100 g oat biscuits
- 50 g butter melted
- 200 g condensed milk ½ a can
- 60 ml lemon juice from approx. 1.5 lemons
- 2 eggs medium
Instructions
- Preheat the oven to 160°C Fan. Line a small baking tray or a loaf tin with baking parchment.
- In a large mixing bowl, crush oat biscuits with the end of a rolling pin. Add melted butter and mix well. Tip the mixture into a tray and press down with a back of the spoon. Make sure it gets into all four corners of the tin. Bake for 10 minutes.
- In the meantime, whisk condensed milk, lemon juice and eggs with an electric whisk until fully combined and volume slightly increased (about 2-3 minutes).
- Pour the lemon mixture on top of the baked oat biscuit base and return to the oven for 15-20 minutes, until the filling sets.
- Once baked, cool completely at room temperature. Then chill for at least two hours in the fridge before slicing and decorating with icing sugar and lemon zest, if you wish.
Nutrition

Toni
This dessert is totally impossible to resist!! Amazing! Thanks for sharing the recipe!
Ieva
You are most welcome, Toni!
Vidya Narayan
Love citrus based desserts! Had to try them and they were delish!
Ieva
Thanks, Vidya! 😍
Gina Abernathy
You had me at lemon. So light, creamy and amazing.
Ieva
Absolutely! We love how easy they are to make too!
Dannii
Any kind of lemon dessert is good with me and these were delicious.
Ieva
Thanks! 💗
Tavo
the lemon slices came out so good! Super easy and so yummy!
Tara
These lemon slices are like little bars of heaven! I couldn’t believe that they only required 5 ingredients. So easy, too!
Ieva
Thanks, Tara! We love an easy dessert!
Claire
Love these lemon slices. Just the right amount of lemon!
Amanda Wren-Grimwood
Can’t believe these were so easy to make. I have to say they didn’t last long and the lemon flavour was perfect.
Ieva
Thanks! 💗
Ana F.
I love everything with condensed milk and this lemon dessert was perfect! The family truly enjoyed and can’t wait to make it again. Thanks for the recipe!
Ieva
What lovely feedback! Thanks so much for trying our recipe! 🙂