The easiest and most delicious Baked Lemon Slice recipe with a creamy and tangy lemon frosting. A classic slice that's ready to eat in less than 1 hour and is perfect for morning tea or school lunchboxes.
When you feel like baking a classic, comforting slice then my baked lemon slice is exactly what you need.
Simple to prepare, the light and fluffy cake-like base is perfectly complemented by the smooth and creamy lemon frosting.
Just like my Easy Chocolate Coconut Slice, Passionfruit Slice, Jelly Slice and Mars Bar Slice, this recipe takes just a few minutes to prepare and is as popular today as it was 50 years ago!
Why You're Going To Love This Recipe
If you've been visiting my blog for a while then you'll know that my key principle is to make delicious food without any fuss.
If it's easy to make, quick, and tastes fabulous - then I'm all in!
And this Baked Lemon Slice recipe is all those things... plus so much more.
- Basic pantry & fridge staples - I wouldn't be surprised if you find that you have all the ingredients on hand already. Made from basic pantry and fridge staples, this is a great recipe to whip up when you want to avoid an extra trip to the supermarket.
- Time saver - just mix the ingredients together in one bowl and then bake - all in just 30 minutes. Wait for the slice to cool and then smother it in luscious creamy frosting.
- Most popular recipe - this is the perfect recipe to enjoy with friends over a coffee. A beautiful freshly baked, moist and tangy lemon slice is always popular.
- Freezer friendly - yes, you can freeze this slice too! Perfect for 'grab and go' lunchbox fillers.
What You Need
There's absolutely no fancy ingredients required for this simple baked lemon slice.
Note: Please scroll to the recipe card at the bottom of the post for ingredient quantities and the full detailed method.
For The Base
- Butter - either salted or unsalted butter can be used in this recipe.
- Caster sugar - I recommend using caster sugar rather than regular granulated white sugar as it dissolves easier when creamed with butter making it the perfect sugar for cakes, cupcakes, slices and desserts.
- Lemon zest - from one lemon. See how to zest a lemon here.
- Eggs - at room temperature.
- Lemon juice - from one lemon, or alternatively use store bought lemon juice.
- Baking powder
- Plain flour - also known as all-purpose flour.
For The Lemon Frosting
- Icing sugar - use pure icing sugar as it will set the frosting firmer than icing sugar mixture.
- Butter - either salted or unsalted butter can be used in this recipe.
- Lemon juice - it is preferable to use fresh lemon juice, but if fresh lemons aren't available then store bought lemon juice makes a great substitute.
Step By Step Instructions
This is just the easiest 4-step baked lemon slice recipe!
Note: Please scroll to the recipe card at the bottom of the post for ingredient quantities and the full detailed method.
Step 1 - Beat
Preheat your oven to 170 degrees celsius (fan forced), and grease and line a square baking tin.
Place butter (that has been softened to room temperature), caster sugar and lemon zest into a large bowl.
Beat the ingredients together until smooth and creamy.
Step 2 - Add Wet Ingredients
Add the eggs and lemon juice and beat well to combine.
Step 3 - Add Dry Ingredients
Fold through the baking powder and flour.
Mix together gently until well combined.
Pour the mixture into your prepared baking tin and place into the oven to bake.
Step 4 - Make The Frosting
Prepare the lemon frosting by sifting the icing sugar into a bowl and then adding the softened butter and lemon juice.
Whisk until the icing is completely smooth.
Once the baked slice base has cooled completely, spread the icing evenly over the slice whilst it is still in the baking tin.
Once the icing has set, remove the slice from the tin to cut and serve.
Tips For Making The Best Lemon Frosting
Follow these tips for a beautiful creamy lemon frosting:
- Use pure icing sugar (as compared to icing sugar mixture) as it will set the frosting firmer than icing sugar mixture. A firmer icing is best when sending the slice in school lunch boxes.
- Sift the icing sugar before using to remove any lumps (pure icing sugar tends to have more lumps than the softer icing sugar mixture so don't miss this step!)
- Use room temperature butter.
- If your frosting is too thick to spread, add a small amount of extra lemon juice and mix again.
- If your frosting is too thin, add some extra sifted icing sugar.
- Whisk the frosting until it's smooth and creamy with no lumps of butter or icing sugar remaining.
Expert Tips & FAQ's
Temperatures given in my recipes are for fan-forced ovens. All ovens are slightly different but to bake in a conventional oven, simply increase the temperature by 10-20 degrees, and keep a close eye towards the end of the baking time to ensure the slice isn't browning too quickly.
This can easily be fixed by adding extra icing sugar (if too thin) or extra lemon juice (if too thick). See my tips above for making the perfect lemon frosting.
You can store this baked lemon slice in an airtight container at room temperature for up to 5 days, or freeze for up to 1 month.
I recommend keeping this baked lemon slice at room temperature so that it stays beautifully soft and moist.
Related Recipes
This Baked Lemon Slice is just so deliciously tangy and moist - the perfect afternoon tea recipe!
If you find that you have a fruit bowl overflowing with lemons, these lemon recipes are always popular:
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Baked Lemon Slice
Ingredients
- 115 g butter softened to room temperature
- 150 g (¾ cup) caster sugar
- lemon zest from 1 lemon
- 2 eggs room temperature
- lemon juice from 1 lemon
- ½ tsp baking powder
- 95 g (¾ cup) plain flour
For the frosting
- 270 g (1 ¾ cup) pure icing sugar sifted, see notes
- 65 g butter softened to room temperature
- 4 tbs lemon juice (extra if needed)
Instructions
Conventional Method
- Preheat oven to 170 degrees celsius (fan-forced). Grease and line a 20cm x 20cm cake tin with baking paper. Set aside.
- Place the butter, caster sugar and lemon zest into a large bowl. Beat until smooth and creamy.
- Add the eggs and lemon juice and beat to combine.
- Fold through the baking powder and flour.
- Spoon the mixture into the prepared tin and bake for 20-25 minutes or until a skewer inserted into the middle comes out clean.
- To prepare the frosting, place the sifted icing sugar, butter and lemon juice into a bowl. Whisk until smooth and creamy. If the frosting is a little too thick, add a bit more lemon juice and whisk again. If too thin, add a little more icing sugar.
- Spread the frosting over the cooled slice and allow to set.
Thermomix Method
- Preheat oven to 170 degrees celsius (fan-forced). Grease and line a 20cm x 20cm cake tin with baking paper. Set aside.
- Place the butter, caster sugar and lemon zest into the Thermomix bowl. Insert the butterfly and mix for 30 seconds, Speed 4. Scrape down the sides of the bowl and repeat until smooth and creamy.
- Add the eggs and lemon juice and mix for 10 seconds, Speed 4, to combine. Remove the butterfly.
- Add the baking powder and flour and mix for 10 seconds, Speed 4. Scrape down the sides and repeat for a further 5 seconds.
- Spoon the mixture into the prepared tin and bake for 20-25 minutes or until a skewer inserted into the middle comes out clean.
- To prepare the frosting, place the icing sugar, butter and lemon juice into the Thermomix bowl and mix for 20 seconds on Speed 4. Scrape down the sides of the bowl with a spatula. Mix for an extra 30 seconds, Speed 4.
- If the frosting is a little too thick, add a bit more lemon juice and whisk again. If too thin, add a little more icing sugar.
- Spread the frosting over the cooled slice and allow to set.
Notes
- Use pure icing sugar (as compared to icing sugar mixture) as it will set the frosting firmer than icing sugar mixture. A firmer icing is best when sending the slice in school lunch boxes.
- If your frosting is too thick to spread, add a small amount of extra lemon juice and mix again.
- If your frosting is too thin, add some extra sifted icing sugar.
- Storing & Freezing - store this slice in an airtight container for up to 5 days, or wrap well and freeze for up to 1 month. Allow to thaw before consuming.
Lauren
What am I doing wrong It’s not mixing nicely when I add the eggs and lemon juice. It’s separating. I just kept going and naked it anyway, but it came out oily and all falling apart. I tried a second time and the same thing happened… could it be the lemons I’m using?? They do seem a bit past perfect. I’m usually a great cook! And I know all your recipes are fabulous so I know it’s not your recipe. Help!
Lucy
Hi Lauren, try and add the eggs very slowly and allow them to mix completely. Add the lemon juice super slowly while combining. And also, it's best if the eggs are at room temp!
Alison Backhouse
Would it work with coconut oil instead of butter for a dairy free option?
Lucy
Hi Alison, I personally havent tried that! I'd suggest using Nuttelex for a dairy-free option as that is a closer substitute to butter. xx
Francesca Magann
I HAVE MADE THIS THREE TIMES IN THE LAST COUPLE OF WEEKS & IT IS SO EASY TO MAKE & DELICIOUS. EVERYONE LOVES IT & ASK FOR IT ALL THE TIME. GREAT RECIPE.
Lucy
Oh I'm so thrilled to hear that!