Introduction

This Creamy Vanilla Slice with Flaky Puff Pastry is a delightful treat combining crisp, golden layers with a rich, silky custard. Perfect for an elegant dessert or a special afternoon snack, this recipe is sure to impress with its classic flavors and satisfying texture.

The image shows multiple pieces of a dessert with three clear layers: the top and bottom layers are light brown, thin, and flaky pastry dusted with white powdered sugar, while the middle layer is thick, creamy, and pale yellow custard with visible tiny dark specks. One piece is lifted and placed on top of another to clearly show the custard filling and the flaky texture of the pastry layers. The dessert is on a white marbled surface, with a blurred white cup of black coffee and a small glass bowl with white sugar cubes in the background. photo taken with an iphone --ar 4:5 --v 7

Ingredients

2 (8½ oz; 490g) sheets of puff pastry, thawed
⅔ cup (133g) granulated sugar

½ cup (60g) cornstarch
¼ tsp kosher salt

3½ cups (795g; 830ml) whole milk, warm
6 large egg yolks, room temperature

1 vanilla bean, cut in half, seeds scraped out, or 2 tsp vanilla bean paste
4 Tbsp (60g) unsalted butter, cold, cubed
Powdered sugar, for dusting

Instructions

Step 1: Preheat your oven to 400°F (200°C) and line two baking trays with parchment paper. Roll out the puff pastry sheets slightly to about 9×9 inches. Prick all over with a fork to prevent puffing during baking. Place the pastry sheets on the trays, then cover each with another sheet of parchment and a second tray to weigh them down.
Step 2: Bake the puff pastry for 35-45 minutes, or until golden and crisp. Begin checking around 30 minutes to avoid overbaking. Once done, set aside and cool completely.
Step 3: Use a serrated knife to carefully trim the edges of the cooled pastry to fit an 8×8-inch square pan. Place the pan on top of the sheet of puff pastry and trim around it without pressing down.

Step 4: In a medium saucepan, whisk together granulated sugar, cornstarch, and kosher salt. Add the egg yolks and whisk until fully combined.
Step 5: Warm the whole milk in a separate saucepan over medium heat until steaming but not boiling.
Step 6: Slowly pour 1 cup of the warm milk into the egg mixture, whisking constantly to temper the eggs. Then gradually pour the tempered eggs back into the saucepan with the remaining milk, whisking until well mixed.

Step 7: Cook the mixture over medium heat, whisking constantly, until it thickens and begins to bubble, about 5-7 minutes. Remove from heat and stir in the vanilla bean seeds and cold, cubed butter. Whisk until the butter melts completely.
Step 8: Line the 8×8 pan with aluminum foil, leaving an overhang for easy removal. Place one pastry sheet on the bottom, pour the warm custard evenly over it (you may strain it beforehand if desired), then smooth with a spatula.
Step 9: Place the second pastry sheet on top and gently press down to adhere. Cover tightly with plastic wrap or foil and refrigerate for at least 4 hours or overnight to set.

Step 10: Lift the slice out of the pan using the foil overhang. Transfer to a cutting board and carefully cut into 9 larger or 16 smaller squares using a serrated knife. Scoring the top gently before cutting can help keep slices neat. Dust with powdered sugar before serving.

Tips & Variations

For extra smooth custard, strain the mixture through a fine sieve before pouring it over the pastry.
If you don’t have a vanilla bean, 2 teaspoons of high-quality vanilla extract can be substituted, but vanilla bean seeds add a lovely texture and aroma.

Use cold butter for the custard to create a glossy finish when stirred in.
Keep the puff pastry sheets weighted down during baking to ensure they stay flat and crisp rather than puffing too much.

Storage

Store the vanilla slice covered in the refrigerator for up to 3 days. Keep it tightly wrapped to prevent the puff pastry from becoming soggy. Reheat briefly in a warm oven to refresh the pastry before serving, if desired, but be gentle to avoid melting the custard.

How to Serve

The image shows a close-up of a square slice of mille-feuille pastry with three layers: a golden brown, thin, flaky puff pastry on the top and bottom, and a thick, creamy, pale yellow custard filling with visible vanilla bean specks in the center. The top puff pastry layer is dusted generously with powdered sugar. Other similar squares are partially visible around it, all placed on a white marbled surface. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I make the custard ahead of time?

Yes, you can prepare the custard a day in advance. Store it in the refrigerator covered with plastic wrap directly on the surface to prevent a skin from forming. Reheat gently before assembling.

What type of puff pastry works best?

Use high-quality store-bought puff pastry sheets for convenience, or homemade if you prefer. Ensure they are fully thawed before rolling and baking for the best texture.