Emelia Jackson’s foolproof vanilla slice is easier to make than you might expect

The vanilla slice is a nostalgic country bakery classic: a thick, wobbly slab of creamy vanilla-flecked custard sandwiched between layers of golden pastry and finished with a sweet glaze. Yet perfecting that balance of flaky pastry and smooth custard can feel like a feat.

By using high-quality store-bought puff pastry and a pastel-pretty ruby grapefruit icing, it becomes a refreshingly simple weekend project – elegant enough to anchor any afternoon tea.

Techniques of the month: Perfectly set custard and neat slicing

Perfectly set custard

Cooking the custard over medium heat while stirring constantly is the best way to prevent lumps and guarantee a silky, firm set. If any lumps do form, simply pulse them out with an immersion blender before assembly.

For the crispiest results, let the custard cool slightly before pouring to avoid steaming the pastry.

Neat slicing

When you’re ready to serve, use a sharp serrated knife to gently saw through the delicate top layer before pressing down to slice through the base.

Ensure the slice is thoroughly chilled and wipe your blade between every cut for a bakery-standard finish.

Tips for success

• Use good-quality frozen puff pastry and thaw it fully before baking.
• Don’t rush the custard cooking – it needs to be thick enough to coat the back of a spoon.
• You can swap out the ruby grapefruit for any citrus you love. Lemon, orange, blood orange and yuzu all work beautifully. Otherwise, stick with tradition by using passionfruit pulp.
• Use a serrated knife or sharp chef’s knife, and wipe it clean between cuts to ensure each square has neat edges.