- 2 8.5-ounce sheets ready-rolled puffed pastry, defrosted [from a 1.1-pound (490-gram) package]
- 3/4 cup granulated sugar
- 6 tablespoons cornstarch
- 1/4 teaspoon fine sea salt
- 1 1/2 teaspoons vanilla bean paste, or 2 teaspoons vanilla extract
- 2 large eggs
- 2 cups whole milk
- 3/4 cup heavy cream
- 3 tablespoons unsalted butter, diced
Line the base and sides of an 8×8-inch cake pan with a large sheet of foil so the excess goes up the sides. I find it can help to first mold the foil over the outside of the baking pan and then transfer it inside, for fewer tears.
Place first cooled square of pastry on a cutting board and use bottom of cake pan to cut it into a square that will fit tightly inside the pan. Repeat with second square. Place first square inside the pan; save second until needed.
Make the custard: In a medium saucepan, whisk together sugar, starch, and salt. Add the eggs, one at a time, whisking until smooth and no pockets of sugar-starch remain before adding the second. Whisk in vanilla bean paste, and then, very gradually, whisking the whole time, pour in milk, then cream. Bring mixture to a simmer over medium heat, whisking the whole time. As the custard begins to bubble, it will thicken. Remove from heat and stir in the butter until it is fully melted. If you want it extra silky-smooth, pour the custard through a fine-mesh sieve before continuing but I never do.
Assemble the squares: Immediately pour the warm custard into the baking pan over the first sheet of puff pastry and spread evenly. Place the second sheet of pastry on top, pressing gently to secure in place.
Chill the squares: Wrap the pan in plastic and refrigerate for at least 4 hours or overnight to allow the custard to fully set. Once chilled and set, use the foil to carefully lift the mixture from the tin. Dust with powdered sugar — I used some strips of paper leftover from a kid quilling project to create a decoration — then use a sharp, serrated knife to cut it into slices.
Do ahead: Stored in a sealed container in the refrigerator, these will keep for a couple of days. They will keep for up to 5 days, but the pastry will soften a bit.
Notes: I took many liberties with this recipe. I re-scaled the recipe for the package size of the brand of frozen puffed pastry most of us have access to in the US, Pepperidge Farm, because I didn’t want us to have to buy two boxes. To do so, I reduced the recipe by about 1/3 to fit in an 8×8-inch pan, rounding off the parts that didn’t scale evenly. I found that rather than cutting the pastry down to size and then baking it — it was hard to predict how much it would shrink — I baked the pastry larger than needed and cut it when it came out of the oven. I have my own shortcut method of making custards/pastry creams and applied it here — no separately warmed milk/cream, so everything is made in one pot.