Mille Feuille (Mil Folhas)

For the pastry cream:
Prepare pastry cream a few hours or a day in advance. Mix cornstarch, flour, egg yolks and sugar in the bowl of an upright mixer. Mix until pale yellow in color, scraping sides frequently. Set aside.

Heat milk and vanilla on medium just until it simmers. Remove from heat.

Temper half of the heated milk into the mixer bowl, whisking as milk is added. Continue whisking to fully incorporate.

Add egg and milk mixture back into the pan with remaining milk. Return to flame and cook, stirring constantly, until it thickens and bubbles. Continue cooking for 1–2 minutes more.

Pour into a clean bowl, immediately cover the top with a sheet of plastic wrap directly in contact with the hot cream. This will prevent a hardened film from forming on top as the cream cools. Allow to come to room temperature. Then refrigerate for at least 1 hour.

For the puff pastry:
Preheat oven to 400° F.

Unfold one defrosted puff pastry sheet and cut into 3 equal lengths. Place cut lengths onto a baking sheet covered with parchment paper. If baking sheet is large enough, you can bake both puff pastry sheets at one time, for a total of 6 cut sections. Otherwise, bake them 3 at a time.

Dock pastry sections by piercing repeatedly with the tines of a fork. Make sure entire surface is docked.
Sprinkle lightly with pinches of granulated sugar.

Place another length of parchment paper on top and weigh the pastry sections down by placing a second baking sheet upright over the parchment paper. Bake for 15 minutes, the remove top baking sheet and parchment paper. Return to oven and bake for 8 minutes, then remove and flip the pastry sections over. Bake for another 8 minutes until dark golden brown.

Place on a cooling rack and allow to cool completely.

For the icing:
Once puff pastry is at room temperature, mix icing by whisking all the ingredients except powdered unsweetened cocoa. Add milk a bit at a time to achieve a nice, thick spreadable icing that is not too runny.

Take about ¼ of the prepared icing and the cocoa and whisk together in another bowl. This will be the color and flavor accent for the design that goes on top of the mille feuille.

To assemble:
Spread ¼ of the pastry cream over one section of puff pastry, top with another section, and spread another ¼ of the pastry cream on that one. Top that one with a third section. Try not to let the pastry cream run down the sides but spread right to the edge of the puff pastry.

Spread about ½ of the white icing over the top, covering the entire sheet. Draw some lines at about 1-inch intervals by piping the chocolate icing out of a small cut in a plastic bag. Pull a toothpick 3 times, about 1 inch apart, down the length of the pastry, dragging the lines of the chocolate into the white icing, creating an intricate pattern. Pull toothpick in one direction only or alternate the pulling of the toothpick in the opposite direction for a more intricate design pattern.

Serve, or chill for until ready to serve.

Cut individual portions with a sharp knife or pizza chopper using downward only movement. Do not saw back and forth or you will dislodge the layers of pastry on the soft pastry cream.