Custard Slice

Creamy, smooth vanilla custard layered between crisp, flaky puff pastry and finished with a classic marbled icing. This custard slice is a timeless dessert that feels both comforting and indulgent, perfect for sharing at gatherings or enjoying as a nostalgic treat with a cup of tea.

Why You’ll Love This Recipe

This recipe delivers that perfect balance between rich custard and light pastry, with a silky texture that slices beautifully when chilled. It uses simple pantry ingredients, is easy to prepare step by step, and the result looks impressive despite being very achievable at home. The marbled icing on top adds a bakery-style finish that makes each slice feel special.

Ingredients

(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)

Puff pastry
2 sheets flaky puff pastry, fully defrosted

Custard filling
⅔ cup custard powder
⅔ cup white sugar
2 teaspoons vanilla essence
1 litre full cream milk
1 large egg
50 g butter

Icing
2 cups icing sugar
25 g butter, softened
4 to 5 tablespoons hot water
1 tablespoon cocoa powder

Directions

Preheat the oven to 220°C fan bake. Line a 21 cm square baking tin with baking paper, making sure it extends up the sides.

Place the puff pastry sheets on a lined oven tray and prick all over with a fork. Bake for 8 minutes, then remove from the oven. Place another baking tray on top and press firmly to flatten the pastry. Return to the oven for another 8 minutes, remove again, press flat once more, and set aside to cool completely.

In a mixing bowl, combine the custard powder, sugar, vanilla essence, and ½ cup of the milk. Stir until smooth. In a separate bowl, whisk together the egg and another ½ cup of milk.

Pour the remaining milk into a medium saucepan and heat over medium heat. Add the custard mixture and bring to a boil, stirring constantly. Once boiling, reduce to a gentle simmer and cook for about 5 minutes until thick.

Add the egg mixture and butter to the custard. Stir continuously for 2 minutes, then remove from the heat and allow the custard to cool slightly.

Trim the cooked pastry sheets to fit the prepared tin. Place one sheet into the base of the tin. Pour the custard evenly over the pastry and smooth to the edges. Top with the second sheet of pastry, pressing down gently.

To make the icing, sift the icing sugar into a bowl. Add the softened butter and hot water, mixing until smooth. Transfer 3 tablespoons of the icing into a small bowl and mix with the cocoa powder, adding a little extra hot water if needed for piping consistency.

Spread the white icing evenly over the top pastry layer. Pipe thin lines of chocolate icing across the surface, then drag a skewer through the lines in alternating directions to create a marbled effect.

Refrigerate for at least 5 hours or overnight until fully set. Slice while cold using a sharp serrated knife, gently sawing through the pastry.

Servings and timing

Servings: 12 slices

Preparation time: 30 minutes
Cooking time: 20 minutes
Chilling time: 5 hours
Total time: approximately 5 hours 50 minutes

Variations

For a lighter flavour, replace half of the milk with reduced-fat milk while keeping the custard creamy.
Add a hint of citrus by mixing finely grated lemon or orange zest into the custard.
Skip the chocolate marbling and finish with plain white icing for a classic bakery-style slice.
Add a thin layer of melted dark chocolate on top instead of icing for a richer finish.

Storage/Reheating

Store the custard slice in an airtight container in the refrigerator for up to 5 days. This dessert is best served cold and does not require reheating. Freezing is not recommended, as the custard texture can change once thawed.

FAQs

Why does the pastry need to be pressed flat while baking?

Pressing the pastry prevents excessive puffing and creates an even, flat surface that holds the custard and icing neatly.

Can I make this recipe ahead of time?

Yes, custard slice is ideal for making a day in advance as it needs time to fully set in the fridge.

What type of milk works best?

Full cream milk is recommended for the creamiest custard texture and best flavour.

How do I stop the custard from becoming lumpy?

Stir constantly while heating and make sure the custard reaches boiling point before reducing the heat.

Can I use a different baking tin size?

Yes, but a smaller tin will create thicker layers, while a larger tin will result in thinner custard and icing.

Why should the slice be cut while cold?

Cold custard holds its shape better, making clean slices without squeezing out the filling.

Can I leave out the cocoa icing?

Absolutely, the slice is still delicious with just a smooth white icing on top.

What knife is best for slicing custard slice?

A sharp serrated bread knife works best to cut through the pastry without crushing the custard.

Can I add extra vanilla flavour?

Yes, you can add an extra ½ teaspoon of vanilla essence if you prefer a stronger vanilla taste.

Is this recipe suitable for children?

Yes, it contains simple ingredients and has a mild, sweet flavour that children usually love.

Conclusion

This custard slice is a classic dessert that never goes out of style. With its creamy filling, crisp pastry layers, and smooth marbled icing, it is a reliable crowd-pleaser that feels both nostalgic and elegant. Whether you are baking for a special occasion or simply craving a comforting homemade treat, this recipe is one you will want to make again and again.

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