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4.72 from 21 votes

Vanilla Custard Slice

This classic vanilla custard slice is delicious, creamy and oh-so-simple. Made with an irresistibly smooth vanilla custard, layers of flaky puff pastry and topped with vanilla icing, this easy slice recipe makes the perfect afternoon tea!
Prep Time15 mins
Cook Time15 mins
Total Time30 mins
Course: Dessert, Snack
Cuisine: Australian
Servings: 16
Calories: 392kcal


  • 2 sheets frozen puff pastry thawed
  • 1 ½ cups caster sugar
  • 1 cup custard powder
  • 4 cups thickened cream
  • 1 ⅓ cup milk
  • 2 tsp vanilla vanilla bean paste or essence

For the icing

  • 2 cups icing sugar
  • 2 tsp butter softened at room temperature
  • 1 ½ tsp vanilla vanilla bean paste or essence
  • warm water (or substitute the water for passion fruit pulp for passion fruit vanilla slice)


  • Pre-heat the oven to 190 °C (374F) and place the two sheets of puff pastry on a flat oven tray lined with baking paper.
  • Using a fork, prick the puff pastry all over so that it doesn't puff up too much while baking.
  • Bake for around 10-15 minutes, or until the pastry has become puffed and flaky, but not browned. It should still be a pale or lightly golden colour.
  • Place the puff pastry on a wire rack to cool.

For the custard filling

  • While the pastry is baking, place the sugar and custard powder into a large saucepan and whisk together.
  • Add the cream, milk and vanilla and whisk until smooth and combined.
  • Over low heat, continue to whisk the custard mixture until it thickens (this may take around 10 minutes). Transfer the custard to a bowl and place a layer of plastic or silicone wrap over the surface of the custard. Refrigerate until cool and set.

For the icing

  • Place all of the ingredients together in a small mixing bowl with a little (1-2 tbs) water and stir until combined. Add a little more water if required, until you reach the desired consistency.

To assemble

  • Place one layer of puff pastry on a flat board or plate.
  • Spoon the thickened custard over the pastry and use a spatula to smooth the edges.
  • Add the second layer of pastry over the top of the custard and top with the vanilla icing, using a flat knife or spatula to spread evenly.
  • Refrigerate in an airtight container and allow to set for at least 4 hours, or overnight, before cutting.
  • To cut the slice, use a clean pair of scissors to cut the top layer of pastry, before running a sharp knife through the remaining layers. This will help to stop the custard from being pushed out the sides. This custard slice will last in the fridge for around 3-4 days. Serve chilled. Enjoy!


This recipe is super simple, but here are a few tips to ensure you get the best results;
  • Cook the custard over a very low heat to ensure that it doesn’t catch and burn on the bottom of the saucepan. It is easy to get impatient and turn up the heat to speed up the thickening process. But whisking continually over low heat will result in a smooth custard, minus the lumps and burnt bits.
  • Thick custard is key! Ensure that you whisk the custard until it is very thick so that it holds its shape in the slice. Thick custard is much easier to cut and will not ooze out the sides.
  • While cooling, cover the custard by placing a plastic or silicone wrap directly onto the surface of the custard. This prevents a skin forming while it is cooling and setting.
  • If possible, make the slice the day before it is required. It is much easier to cut once the custard and icing have had time to set. At the very least, leave the slice in the refrigerator for 4 hours to set before cutting.
  • This is my favourite tip and results in much cleaner slices. Cut the top layer of pastry with a clean pair of scissors before using a sharp knife to cut through the rest of the vanilla slice. Attempting to cut through the top layer with a knife can push the pastry down too far, resulting in the custard being forced out the sides of the slice. Using scissors to cut the top layer prevents this crime against custard slice from happening!
  • Keep the puff pastry as flat as possible. Pricking holes with a fork helps to prevent the pastry puffing up too much. Once the pastry is cooked, you can gently press it down with your hands (after it has cooled slightly).
  • For passionfruit vanilla slice, replace the water and vanilla in the icing mixture for passionfruit pulp.


Calories: 392kcal | Carbohydrates: 43g | Protein: 3g | Fat: 24g | Saturated Fat: 13g | Cholesterol: 71mg | Sodium: 64mg | Potassium: 105mg | Fiber: 1g | Sugar: 35g | Vitamin A: 657IU | Vitamin C: 1mg | Calcium: 70mg | Iron: 1mg