Vegan vanilla slice - these vegan custard slices consist of a smooth, creamy vanilla custard sandwiched between two layers of flaky puff pastry and are topped with a sweet, tangy passion fruit glaze.

They are easy to make and just as good as the classic bakery treat but with no eggs or dairy!

Close up of the vegan vanilla slices topped with passion fruit glaze.

What Are Vanilla Slices?:

Vanilla slice, also known as custard slices, are a classic bakery treat that is common in the UK and Australia.

They consist of a thick layer of vanilla flavoured set custard sandwiched between puff pastry and topped either with a sweet glaze or a dusting of icing sugar. They are similar to French mille-feuille but with fewer layers.

A labelled photo of the ingredients needed to make vegan vanilla slice.

Ingredient Details:

Custard powder: This sets the custard filling and adds flavour and colour. Most custard powder is vegan friendly (I use Bird's). You can swap it for cornstarch in a pinch but do use custard powder if you can.

Vegan butter: I add some vegan block butter to the custard filling to make it richer and creamier and also to help it set. You can use spreadable if that is all you have but your custard may be softer so I would recommend increasing the custard powder to 110g in this case.

Milk: I recommend using soya milk for the custard as it is creamy with a neutral flavour. Any other kind of milk should work, but the flavour may come through and depending on which one you choose the custard may not be as creamy.

Vanilla: I use vanilla bean paste but you can also use the seeds scraped out of a vanilla pod or just use vanilla extract.

Sugar: You will need either caster or granulated sugar for the custard and icing (powdered) sugar for the glaze and for dusting the pastry. I do not recommend swapping these for any other kind of sugar or sweetener.

Puff pastry: Most shop-bought puff pastry is vegan friendly (unless it is labelled "all butter"), but do check the packet just in case. Use ready rolled pastry if you can for convenience.

Passion fruit: A simple passion fruit glaze adds a tangy, fruity, citrus flavour to these vegan vanilla slices that works wonderfully with the creamy custard filling. It is optional however, you can simply dust them with a little icing sugar before serving.

Close up of a vegan vanilla slice with a forkful removed.

How To Make Vegan Vanilla Slice:

(Full measurements and instructions can be found in the recipe card at the bottom of the page)

Step 1: Unroll one sheet of pastry and lay it on a baking tray, keeping the paper underneath. Dust with a little icing sugar, then cover with another sheet of baking paper. Place another baking tray on top and then weigh this down with two loaf tins filled with baking beans.

Step 1, the weighted down pastry before baking.

Step 2: Bake for 35 minutes. Slide the pastry onto a cooling rack and repeat with the other sheet of pastry.

Step 3: Use a sharp knife to cut each piece of pastry into a 23cm square; use your tin to guide you. Place one square into the base of the lined tin.

Step 4: Cut the other pastry square into 10 rectangles, by slicing it in half horizontally and then into 5 vertically.

Step 4, the top pastry sheet divided into rectangles.

Step 5: To make the custard, place the custard powder and sugar in a large saucepan. Gradually whisk in the milk a little at a time to avoid lumps. Add the vanilla paste.

Place the pan over a medium heat and stir constantly with a balloon whisk until the custard comes to a boil and thickens considerably.

Remove from the heat, add the butter and stir until melted and combined.

Step 6: Immediately pour the hot custard over the pastry base in the tin and spread it level.

Step 7: Top the custard with the pre-cut pastry slices. Chill for about 4 hours until set.

Step 7, the assembled slices with the pastry portions on top.

Step 8: When you are ready to serve them, carefully lift the whole slice out of the tin and use a sharp knife to slice it into portions along the pre-cut pastry lines.

Top with a glaze or simply dust with icing sugar to serve.

The sliced and glazed custard slices on a sheet of baking paper with passion fruit shells and a bowl of passion fruit glaze.

Top Tips:

Weighing the pastry down while it cooks controls the rise and helps to make sure it is nice and crisp.

Cutting the top sheet of pastry into portions BEFORE assembling the slices makes it much easier to cut them when you are ready to serve; that way there is no risk of squishing the custard trying to cut through the pastry.

These vegan vanilla slices are best eaten as fresh as possible, as soon as the custard has set, as the pastry will soften over time. They will keep in the fridge for around 3 days but the fresher they are eaten the better.

The custard is a firmish set so that the bars are easy to slice neatly. It is still silky smooth and melt-in-the-mouth, but if you prefer a softer set then you can reduce the custard powder to 70g.

Instead of the passion fruit icing you can simply dust the vegan vanilla slices with icing sugar or make a simple glaze by mixing icing sugar with a little milk, water or lemon juice to make a pourable icing.

I prefer to add the icing after cutting the slices into bars as it is neater. Simply spoon some icing on top of each slice and use the back of a teaspoon to spread it out.

Two vegan vanilla slices on a white plate with dessert forks.

More Vegan Dessert Bars Recipes:

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5 from 2 votes