1 sheet frozen puff pastry
2 cups milk
1 vanilla bean or 3 teaspoons of vanilla extract.
5 egg yolks.
2/3 cup sugar
1/3 cup corn starch
1 cup butter
powdered sugar for decorating.
Preheat oven to 425 F. Divide frozen puff pastry into two equal pieces, poke at 1 inch intervals with a fork, place on a parchment lined baking sheet, top with parchment, and an upside down cooling rack. Bake for 15 minutes, remove top parchment and cooling rack, bake at least 2 minutes more or until golden brown, cool
Pour milk into a saucepan, slice vanilla bean lengthwise and scrape out seeds and add to milk (or vanilla extract) heat almost to boil
In a bowl beat egg yolks and sugar until light yellow and fluffy, add corn starch and mix until well combined, very slowly (a spoonful at a time in the beginning) add hot milk, stirring constantly
Return mixture to saucepan and cook over medium heat, stirring until very thick, some say it should coat the back of a spoon and running your finger through it should leave a clear path, cool to room temp covered with plastic wrap, pushed down on top of the custard to prevent a skin from forming
When completely cool, whisk in softened butter.
Depending on the height of the puff pastry, either use one piece as the bottom crust or spilt one and use the bottom half, spread with pastry cream, cover with the second, top half and press gently, use a spatula to smooth out the sides, refrigerate overnight.
The next day, cut into rectangles with a light sawing motion, not with pressure.
Before serving, generously dust with powdered sugar.