Homemade, creamy custard sandwiched between layers of flaky puff pastry topped with a simple glaze. This nostalgic recipe for custard slice is sure to be popular with friends and family.
In a recent team meeting, we were thinking about our favourite recipes that weren't yet on the website. Custard Slice popped into my head instantly!
This recipe takes me right back to childhood. Whether they were homemade, a bakery treat or bought from the high school tuck shop, there's just something so nostalgic about custard slice.
If you love custard like me, why not try my Crème Brûlée recipe? It's actually not as complicated as you might think and the results are so tasty! Or for an impressive tart, why not try my Fresh Berry Custard Tart.
Jump to:
Ingredient notes:
- Pastry: This custard slice is made with flaky puff pastry which is crucial to the recipe.
- Egg: I used a standard size 7 egg in this recipe.
- Milk: Yes, there is a whole litre of milk in the custard. That's what makes it so creamy!
Note: Scroll to the recipe card for the ingredients, quantities and the full method.
Step by step instructions:
Preheat the oven to 220°C fan bake. Line a 21cm square tin with baking paper including up the sides. Place the pastry sheets on a lined oven tray and prick all over with a fork. Cook for 8 minutes then remove from the oven. Use a baking tray to firmly press the pastry down flat. Return to the oven for a further 8 minutes. Remove from the oven again and press down flat one more time, then leave to cool.
In a mixing bowl combine the custard powder, sugar, vanilla and ½ a cup of milk. Mix until smooth. Crack the egg into a separate bowl with ½ a cup of milk. Whisk to combine.
Pour the remaining 3 cups of milk into a medium saucepan over a medium heat. Add the custard mixture to the milk and bring to the boil. Reduce to a simmer, then stir until thickened, about 5 minutes.
Add in the egg mixture and butter. Stir for 2 minutes then set aside to cool.
Trim both pieces of the pastry to fit the tin. Press one piece into the lined tin.
Pour the custard over the pastry spreading out to the edges. Cover with the second piece of pastry, press down gently.
Sift the icing sugar into a mixing bowl, add the butter and boiling water, mix till smooth. Take 3 tablespoons of icing and place in a small bowl. Add the cocoa powder and mix to combine. Add extra hot water if needed. Place chocolate icing in a piping bag or small snap lock bag.
Smooth the white icing over the slice. Then snip the corner off the piping bag creating a 1-2mm opening. Draw lines of chocolate icing across the slice then quickly use a wooden skewer drag the tip through the lines in alternating directions.
Set in the fridge for at least 5 hours or overnight. Cut while cold with a sharp serrated bread knife sawing through the pastry.
Recipe FAQs:
This process helps to make a uniform looking slice, so you can get an even and flat layer of icing on top. The fork pricks help to keep it from rising as does squashing the pastry as it cooks. If we only flattened it at the end, the pastry will be set puffed up and just flake into little pieces.
Sure, just cut your pastry to fit after it has cooked. If the tray is much smaller the custard layer will be thicker and harder to slice, a larger tin will make the custard layer and icing thinner.
Storage:
Store in an airtight container in the fridge for up to 5 days.
Top tips:
Make sure you use a sharp knife to cut the slice. Saw through the pastry so the custard doesn't squash out the sides.
The custard needs to come to the boil for it to thicken, then you can reduce the heat. You will notice it thicken up a lot once it reaches boiling point, it should bubble.
Related Recipes:
Made this recipe?
Please click on the stars below to rate it or, write a review!
Custard Slice
Homemade creamy custard, sandwiched between layers of flaky puff pastry topped with vanilla icing with chocolate swirls.
Ingredients
- 2 sheets flaky puff pastry, defrosted
- ⅔ cup custard powder
- ⅔ cup sugar
- 2 tsp vanilla essence
- 1L milk
- 1 egg
- 50g butter
Icing
- 2 cups icing sugar
- 25g butter, softened
- 4-5 Tbsp hot water
- 1 Tbsp cocoa
Instructions
- Preheat the oven to 220°C fan bake.
- Line a 21cm square tin with baking paper including up the sides.
- Pastry: Place the pastry sheets on a lined oven tray and prick all over with a fork. Cook for 8 minutes then remove from the oven.
- Use a baking tray to firmly press the pastry down flat. Return to the oven for a further 8 minutes. Remove from the oven again and press down flat one more time, then leave to cool.
- Custard: In a mixing bowl combine the custard powder, sugar, vanilla and ½ a cup of milk. Mix until smooth.
- Crack the egg into a separate bowl with ½ a cup of milk. Whisk to combine.
- Pour the remaining 3 cups of milk into a medium saucepan over a medium heat. Add the custard mixture to the milk and bring to the boil. Reduce to a simmer, then stir until thickened, about 5 minutes.
- Add in the egg mixture and butter. Stir for 2 minutes then set aside to cool.
- Assemble: Trim both pieces of the pastry to fit the tin. Press one piece into the lined tin. Pour the custard over the pastry spreading out to the edges.
- Cover with the second piece of pastry, press down gently.
- Icing: Sift the icing sugar into a mixing bowl, add the butter and boiling water, mix till smooth.
- Take 3 tablespoons of icing and place in a small bowl. Add the cocoa powder and mix to combine. Add extra hot water if needed. Place chocolate icing in a piping bag or small snap lock bag.
- Smooth the white icing over the slice. Then snip the corner off the piping bag creating a 1-2mm opening. Draw lines of chocolate icing across the slice then quickly use a wooden skewer drag the tip through the lines in alternating directions (see photo).
- Set in the fridge for at least 5 hours or overnight. Cut while cold with a sharp serrated bread knife sawing through the pastry.
Notes
- Use a sharp knife to cut or saw through the pastry so the custard doesn't squash out the sides.
- The custard needs to come to the boil for it to thicken, then you can reduce the heat. You will notice it thicken up a lot once it reaches boiling point, it should bubble.
Nutrition Information:
Yield: 12 Serving Size: 1Amount Per Serving: Calories: 258Total Fat: 10gSaturated Fat: 5gTrans Fat: 0gUnsaturated Fat: 4gCholesterol: 44mgSodium: 113mgCarbohydrates: 39gFiber: 0gSugar: 34gProtein: 4g
Nutritional values are approximate. Please use your own calculations if you require a special diet.
Thank you for checking out this recipe. I hope you enjoy making and eating it! If you have any questions, queries or feedback, please feel free to leave a comment below.
If you don't already follow me, head over to my Instagram, Facebook or TikTok pages to keep up to date with all my new recipes.
Vanya
Rachael says
My oven does not have a fan bake setting, what temperature should I put it at?
Thanks. 🙂 .
Vanya Insull says
I just had a quick Google and it looks like you increase the temperature by 10-20 degrees to convert to conventional oven temperature (for example 160 degrees fan bake / 180 degrees conventional oven). I hope that helps? You might need to keep an eye on the pastry when it is in the oven to make sure it doesn't burn.
Kazzee says
Hey Vanya
I made this Custard square/slice at wknd, very delicious, I’ve found my puff pastry is separating from the custard upon cutting. Like literally sliding off custard, both top and bottom.
What did I do wrong?
Thanks awaiting your reply so I can have another go lol
VJ cooks says
Make sure you layer the custard and pastry while it’s still a bit warm — if it’s too cold or firm, it won’t spread and stick to the pastry well. Also use the side you pricked with a fork against the custard so it grips better. And when cutting, a sharp serrated knife works best to saw through without pulling the layers apart. That should do the trick!
Paula says
Do you think this could be made without the egg? (egg allergy)
VJ cooks says
Oh the egg is quite important in this recipe. To avoid disappointment I'd recommend looking for a specific, egg-free custard square recipe that's been tested for that purpose.
Frances Bolger says
Make in a cream slice instead with a layer of jam and then whipped cream. It’ll be hard to make a good custard without egg. Unless you try adding gelatin or cornflour to the alpro custard to thicken it
viv says
Just google "vegan custard recipe", there are plenty out there!
Andrew says
My puff pastry sheets wont fit any of My flat baking trays do I need to cut it prior to cooking
VJ cooks says
Do you have a roasting dish or anything bigger you can cook it in? It doesn't need to be flat. Otherwise yes, cut it prior to cooking 🙂
Connie says
what is a size 7 egg? Usually eggs are referred to as small, medium, large or extra large...not a size 7
VJ cooks says
What country are you in Connie? In New Zealand, most eggs are identified by their graded size. A size 7 is the equivalent of a large egg.
Frances says
Do you have to use a square cake tin or can you use a square plastic container
VJ cooks says
Yes that would be fine. The square cake tin has sharper edges which help the pastry to stay nice and square. Some plastic containers are slightly rounded on the edges which just means the pastry might get a little crushed. But won't impact the flavour!
AC says
Would an extra egg yolk help with the colour/flavor? Or will it mess up the thickness and how it sets?
VJ cooks says
Custard is very precarious! Add an extra yolk at your own risk!