Mary Berry Custard Slice Recipe

Mary Berry Custard Slice is made with two layers of buttery, crisp puff pastry sandwiching a thick, rich crème pâtissière (set custard). It is finished with a glossy glacé icing and the signature chocolate feathered design that gives it a professional bakery look. This nostalgic tea-time treat relies on a sturdy, cornflour-thickened custard that holds its shape perfectly when sliced, avoiding the common “squash” effect of creamier fillings.

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Mary Berry Custard Slice Ingredients

For the Pastry

• 1 x 375g sheet Ready-Rolled Puff Pastry: (All-butter is best). Mary recommends ready-rolled for uniform thickness.
• Icing Sugar: For dusting the pastry before baking.

For the Custard Filling (Crème Pâtissière)

• 600ml (1 pint) Full-Fat Milk: Creamy milk is essential for the texture.
• 1 Vanilla Pod: Split, or 1 tsp high-quality vanilla bean paste.
• 4 Large Egg Yolks: Enriches the custard.
• 100g (4 oz) Caster Sugar: Sweetens the filling.
• 50g (2 oz) Cornflour: (Cornstarch). The critical thickening agent that sets the slice.
• 50g (2 oz) Butter: Cubed. Adds gloss and stability to the custard.

For the Topping

• 300g (11 oz) Icing Sugar: Sifted.
• 2-3 tbsp Water: To mix.
• 50g (2 oz) Dark Chocolate: Melted, for the feathering.

How To Make Mary Berry Custard Slice

1. Prep the Pastry: Preheat the oven to 220°C (425°F/Gas 7). Unroll the pastry onto a baking sheet lined with parchment paper. Cut the pastry into two equal rectangles (approx. 12 x 30cm). Prick them all over with a fork and dust with icing sugar.
2. Bake Flat: Place a sheet of parchment paper over the pastry, then place a second baking sheet (or wire rack) directly on top. This weights the pastry down. Bake for 15–20 minutes until golden and crisp. (The weight prevents it from puffing up unevenly). Cool on a wire rack.
3. Infuse Milk: Pour the milk into a saucepan. Scrape the seeds from the vanilla pod into the milk (add the pod too). Heat gently until just below boiling. Remove the pod.
4. Make Custard Base: In a bowl, whisk the egg yolks, caster sugar, and cornflour together until pale and smooth.
5. Thicken: Pour the hot milk onto the egg mixture, whisking constantly. Return the mixture to the clean saucepan. Cook over medium heat, whisking vigorously, until the mixture boils and thickens into a dense paste.
6. Enrich: Remove from the heat and beat in the butter until melted and combined. Transfer to a bowl, cover the surface directly with cling film (to prevent a skin forming), and let it cool until firm.
7. Assemble: Place one strip of pastry on a board. Spread the cooled, thick custard evenly over it. Place the second strip of pastry on top, pressing down very gently.
8. Ice: Mix the icing sugar with enough water to make a thick, spreadable icing. Spread this over the top pastry layer.
9. Feather: Place the melted chocolate in a piping bag (or small baggie with the corner snipped). Pipe thin parallel lines of chocolate across the width of the white icing. Immediately drag a cocktail stick through the lines—first one way, then the other—to create the feathered effect.
10. Set and Slice: Allow the icing to set. Using a sharp serrated knife, use a gentle sawing motion to trim the edges and cut into slices.

Recipe Tips

• The Serrated Knife: Cutting custard slices is notoriously difficult. Use a very sharp serrated bread knife and use a sawing action. Do not push down, or the custard will squidge out the sides.
• Thick Custard: The custard must be very thick (almost like a paste) before cooling. If it is runny in the pan, keep cooking it until the cornflour activates fully.
• Pastry Crispness: Baking the pastry between two trays is Mary’s “technical challenge” secret. It compacts the layers, making them crisp and flaky but flat enough to stack.
• Timing: Assemble the slices shortly before serving. If they sit for too long (over 6-8 hours), the moisture from the custard will eventually make the pastry soggy.

What To Serve With Mary Berry Custard Slice?

• Tea: The classic pairing is a cup of English tea.
• Fresh Berries: Serve with a few raspberries on the side to look pretty.
• Coffee: A latte works well with the creamy vanilla filling.

How To Store Leftovers Mary Berry Custard Slice

• Refrigerate: Store in the fridge for up to 2 days. The pastry will lose its crispness over time.
• Freezing: Not recommended. The cornflour custard tends to weep and split when thawed, and the pastry becomes chewy.

Mary Berry Custard Slice Nutrition Facts

• Calories: ~420 kcal
• Fat: 22g
• Carbohydrates: 50g
• Protein: 6g

Nutrition information is estimated per slice.

FAQs

Try More Recipes:

• Mary Berry Manor House Cake Recipe
• Mary Berry Pecan Pie​ Recipe
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