Step 1

Preheat the oven to 180 Celsius or 350 Fahrenheit.

Step 2

Cut the puff pastry into 3 equal rectangles. Arrange on a baking tray lined with baking paper.

Step 3

Poke generously with a fork and sprinkle with sugar.

Step 4

Top with another sheet of baking paper and lay a cooling rack on top of the baking paper.

Step 5

Bake for about 30 minutes until golden brown.

Step 6

In the meantime, make the pastry cream.

Step 7

Cut open and scrape out the vanilla bean.

Step 8

Place the vanilla and milk in a pot and bring to a boil. Reserve about ¼ of the milk to mix together with the cornstarch.

Step 9

Mix together the egg yolks and sugar in a bowl.

Step 10

Add the cornstarch and reserved milk. Mix until well incorporated.

Step 11

Once the milk in boiling, begin ladeling the hot milk into the egg and sugar mixture while continuously stirring. Finally, add all the milk.

Step 12

Return everything to the pot through a strainer, and while continuously stiring, slowely bring the mixture, once again, to a boil. Remove from heat and add the butter. Stir.

Step 13

Transfer the pastry cream onto a tray lined with plastic wrap and wrap the cream tightly, removing all air. Refrigerate.

Step 14

Once the baked puff pastry had cooled off, it is time to build the Napoleons.

Step 15

Pipe the pastry cream evenly onto one of the puff pastry rectangles. Top with the second puff pastry. Repeat by piping the pastry cream onto the puff pastry and top with the third puff pastry rectangle, BOTTOM SIDE UP. This ensure a flatter surface for the decoration.

Step 16

Mix together the powdered sugar, corrn syrup, butter, and milk removing all clumps.

Step 17

Pour ¾ of the icing over top the pastry. Spread evenly with an offset spatula.

Step 18

Add the cocoa powder to the remaining icing and stir. With a piping bag, pipe lines across the pastry. Using a toothpick, drag the icing down the pastry creating the traditional decoration.

Step 19

Let dry for about 15 minutes.

Step 20

With a sharp, serated knife, carefully trim the edges of the pastry cleaning the knife after each cut, and finally, cutting the single Napoleons.

Step 21

Enjoy!