The Ultimate Vanilla Custard Slice Recipe (Creamy Napoleon Dessert)

 

There are desserts that feel timeless — classics that never go out of style — and one of those is the Vanilla Custard Slice, also known in some countries as Napoleon Slice. This decadent dessert combines layers of crispy pastry with thick, creamy vanilla custard, topped with a dusting of powdered sugar. It’s a treat that looks luxurious but is surprisingly easy to make at home.

If you’ve ever bought one of these slices from a bakery and wondered whether you could recreate it in your own kitchen, the answer is yes — and it may taste even better than store-bought. This long and detailed guide will walk you through every step, answer all your questions, and give you tips to make your custard slice turn out perfect every single time.

Why You’ll Love Vanilla Custard Slice

 

• Creamy yet light: The custard filling is silky and luscious without being too heavy.
• Flaky pastry: The crispy puff pastry layers balance the creaminess perfectly.
• Impressive presentation: Cut into neat squares, it looks bakery-worthy.
• Simple ingredients: You don’t need anything fancy — just milk, eggs, sugar, and pastry.
• Versatile dessert: Perfect for family gatherings, holidays, birthdays, or even a casual tea-time treat.

Ingredients

 

For the Pastry Layers:

• 2 sheets of puff pastry (homemade or store-bought)
• A little flour for rolling

For the Custard Filling:

• 4 cups (1 liter) whole milk
• 1 cup (200 g) sugar
• ½ cup (60 g) cornstarch
• 6 large egg yolks
• 2 tablespoons butter
• 1 teaspoon pure vanilla extract (or the seeds of 1 vanilla bean)
• ½ cup (120 ml) heavy cream (optional, for a lighter mousse-like filling)

For Topping:

• Powdered sugar, for dusting

Step-by-Step Instructions

 

Step 1: Bake the Puff Pastry

1. Preheat your oven to 400°F (200°C).
2. Roll out your puff pastry sheets to fit your pan.
3. Place pastry sheets on a lined baking tray.
4. Prick with a fork to prevent over-puffing.
5. Cover with parchment paper and another baking tray to keep them flat.
6. Bake for 15–20 minutes until golden and crisp.
7. Cool completely.

Step 2: Make the Vanilla Custard

 

1. Heat the milk and vanilla in a saucepan until it’s warm but not boiling.
2. In a bowl, whisk egg yolks, sugar, and cornstarch until smooth.
3. Slowly pour warm milk into the egg mixture while whisking (to avoid scrambling the eggs).
4. Return mixture to saucepan and cook over medium heat, whisking constantly until it thickens.
5. Remove from heat, stir in butter until melted.
6. Let cool slightly. For extra creaminess, fold in whipped heavy cream once the custard has cooled.

Step 3: Assemble the Custard Slice

 

1. Line a square dish with parchment paper.
2. Place one puff pastry sheet at the bottom.
3. Pour the custard filling on top and spread evenly.
4. Place the second pastry sheet on top, pressing gently.
5. Refrigerate for at least 4–6 hours, or overnight for best results.

Step 4: Serve and Enjoy

 

1. Dust generously with powdered sugar.
2. Cut into neat squares or rectangles with a sharp knife.
3. Serve chilled and enjoy the creamy-crispy balance.

Expert Tips for Success

 

• Chill well: Don’t skip refrigeration — it helps the custard set properly.
• Sharp knife: Warm and clean your knife before slicing for perfect edges.
• Prevent soggy pastry: Always cool the custard before layering it on the pastry.
• Make-ahead dessert: Ideal for preparing the night before an event.

Variations You Can Try

 

• Chocolate Custard Slice: Add melted chocolate to the custard for a rich twist.
• Strawberry Custard Slice: Add a layer of fresh strawberries between the custard and top pastry.
• Caramel Custard Slice: Drizzle caramel sauce over the custard before adding the top layer.
• Gluten-Free Option: Use gluten-free puff pastry and cornstarch.

Serving Suggestions

 

This dessert pairs beautifully with:

• Fresh berries on the side
• A drizzle of chocolate or caramel sauce
• A dollop of whipped cream
• A cup of hot coffee or tea

Storage Instructions

 

• In the fridge: Store in an airtight container for up to 3 days.
• Do not freeze: Custard doesn’t freeze well — it can separate once thawed.

Frequently Asked Questions (FAQ)

 

1. Can I make custard slice in advance?
Yes! In fact, it’s best to make it the day before so the custard has time to set.

2. Can I freeze custard slice?
Freezing is not recommended because the custard may lose its creamy texture.

3. What is the difference between custard slice and mille-feuille?
They are very similar! Mille-feuille usually has more layers and may include whipped cream or icing, while custard slice is simpler with just pastry and custard.

4. Can I use store-bought custard instead of making it?
Yes, but homemade custard always tastes fresher and richer.

5. Why is my custard runny?
It probably didn’t cook long enough to thicken. Make sure you whisk continuously until it coats the back of a spoon.

Final Thoughts

 

The Vanilla Custard Slice is a dessert that feels indulgent, elegant, and comforting all at once. With flaky pastry, silky custard, and a touch of sweetness from powdered sugar, it strikes the perfect balance of textures and flavors. This recipe is beginner-friendly, requires simple ingredients, and delivers bakery-quality results right from your own kitchen.

If you’re searching for a show-stopping dessert that everyone will remember, this custard slice is the one. Once you try it, it will surely become a family favorite for years to come.