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Vanilla custard slice topped with an icing glaze.

Vanilla Custard Slice

This delicious easy vanilla custard slice consists of a delightful creamy vanilla custard filling sandwiched between two layers of puff pastry and topped off with a simple icing glaze. A true classic!
5 from 1 vote
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Prep Time: 20 mins
Cook Time: 20 mins
Setting time: 4 hrs
Servings: 8 slices
Calories: 569kcal
Author: Mary-Lou


  • 8"x8" square cake tin


  • 300 grams puff pastry plus or minus
  • 750 mL milk
  • 2 teaspoons vanilla extract
  • 150 grams granulated sugar
  • 3 eggs large
  • 125 mL water
  • 60 grams custard powder
  • 60 grams butter
  • 240 grams icing sugar powdered or confectioners sugar
  • 3-6 tablespoons milk
  • 1 teaspoon vanilla extract


  • Line an 8"x8" square cake tin either with tin foil or baking paper with an overhand. This allows the custard slice to be removed once it has been set much easier. Set the cake tin aside.
  • Preheat the oven to 180­°C/350F. Line two baking sheets with baking paper. If rolling out the pastry, roll it out to about 5mm thick, and at least an inch or 2.5cm wider than the cake tin being used for the slice.
    300 grams puff pastry
  • Place the pastry on the line baking sheets. Prick the pastry all over with a fork, about 2cm apart. Bake the pastry for 25 to 30 minutes or until golden brown. Remove the pastry from the oven and allow it to cool.
  • Once the pastry has cooled, trim the pastry to fit inside the cake tin using a serrated knife. Place one of the pastry sheets at the bottom of the cake tin. Keep the second aside while making the custard filling.
  • Gather all the ingredients for the custard filling. In a medium-large sized saucepan, bring the milk and vanilla extract to a boil, this will take a few minutes.
    750 mL milk, 2 teaspoons vanilla extract
  • While the milk is heating, whisk together the eggs and water until well combined. Then add in the custard powder and whisk until there are no more lumps.
    3 eggs, 125 mL water, 60 grams custard powder
  • Once the milk has come to a boil, remove from the heat, add in the sugar and whisk until dissolved.
    150 grams granulated sugar
  • While still off the heat, slowly pour in the egg mixture while whisking consistently. Once the egg mix has been completely mixed in.
  • Place the custard mix back on the heat and cook the custard while continually whisking until it is very thick, about 7 to 10 minutes of cooking.
  • Take the custard off the heat and add the butter in small chunks, whisking until the chunk is completely incorporated before adding the next chunk of butter.
    60 grams butter
  • Pour the cooked custard over the pastry in the cake tin, and smooth out with a spoon or offset spatula. Then place the second layer of pastry and gently press it into the custard. Allow it to cool at room temperature for an hour before placing it in the fridge to set for 3 to 4 hours or overnight.
  • Once the custard slice has set, whisk together the icing sugar, vanilla and milk (start with 4 tablespoons and increase when needed) until you have a nice pourable glaze. Pour over the top of the custard slice and allow to set for an hour.
    240 grams icing sugar, 3-6 tablespoons milk, 1 teaspoon vanilla extract
  • Using the overhangs, remove the slice from the tin and slice using a serrated knife.


  • Before lining the cake tin, it may help to cut out a piece of baking paper the size of the inside of the tin. Then place this template on the top of the pastry once it has baked to make trimming to size easier.
  • Pricking the pastry is essential in allowing the pastry to rise evenly during the baking and also keeps the pastry from rising too much.
  • Prepping ingredients before cooking the custard filling is important as once the cooking process begins, it can go really quickly.


Serving: 1slice | Calories: 569kcal | Carbohydrates: 77g | Protein: 9g | Fat: 26g | Saturated Fat: 10g | Polyunsaturated Fat: 3g | Monounsaturated Fat: 11g | Trans Fat: 0.3g | Cholesterol: 109mg | Sodium: 227mg | Potassium: 245mg | Fiber: 1g | Sugar: 54g | Vitamin A: 459IU | Vitamin C: 0.03mg | Calcium: 159mg | Iron: 1mg

Nutrition information is an estimate. If scaling the recipe remember to scale your cook and bakeware accordingly.

Did you make this recipe?Mention @marylou_saltyginger on Instagram and tag or #saltygingerblog so that I can see your creations!
Course :Dessert
Cuisine :Australian, British, New Zealand, South African
Keyword :Custard Slice, Custard Square, Vanilla Slice