Mille Feuille

For the Pastry Cream

1. Slice a vanilla bean down the middle and use a spoon to scrape out the seeds.
2. Transfer the milk and vanilla seeds to a medium pot and place over medium-high heat.
3. Bring to a boil whisking occasionally then immediately turn off the heat and set aside to infuse for 15 minutes.
4. In a bowl, whisk the sugar and corn starch together then add the egg yolks and whisk until light and fluffy.
5. Whisk in 1/4 cup of the hot milk mixture until incorporated. Whisk in the remaining hot milk mixture, reserving the saucepan.
6. Pour the mixture through a strainer back into the saucepan. Cook over medium-high heat, whisking constantly, until thickened and slowly boiling.
7. Remove from the heat and stir in the butter. Let cool slightly. 
8. Cover with plastic wrap, lightly pressing the plastic against the surface to prevent a skin from forming.
9. Chill at least 2 hours or until cooled.

For the Pastry Layers

1. Thaw your puff pastry on the counter for about 45 minutes then unfold one sheet onto a lightly floured surface. Preheat oven to 400F.
2. Roll out to about 1/16 an inch then use a knife or pizza cutter to cut 2x4 inch rectangles.
3. Line a baking sheet with parchment paper then place the first batch of rectangles about 2 inches apart. Place another sheet of parchment on top then cover with another baking sheet. Bake for about 11 minutes rotating tray halfway through. Remove from oven and transfer to a wire rack to cool. Repeat process with 1/2 of the remaining sheet of puff pastry for the additional rectangles. You can clean up the edges with a sharp knife if desired.

For the Glaze

1. Add the powdered sugar to a large bowl then pour in the vanilla extract and 3 tablespoons of milk whisk together and add more milk as needed. You want a spreadable consistency but not a watery "flooding" consistency.
2. Transfer about 1/3 cup of the glaze to a different bowl and add the cocoa powder an another tablespoon of milk. Whisk together until smooth. Add more milk as needed so the chocolate glaze matches the vanilla glaze in consistency. Transfer each batch of icing to a piping bag. You can use a small round tip like a #4 for the chocolate or just snip the tip off.

For the Assembly

1. Lay out 9 rectangles onto a wire rack over a piece of paper. Spread the vanilla icing onto each rectangle then pipe stripes of chocolate onto each one. Use a toothpick, skewer, or knife to create the chevron pattern by dragging the tool across the chocolate stripes in alternating directions. Set aside to set.You can speed things up by arranging the tops in a grid where they're all touching then pipe the chocolate and create the chevrons.
2. Whip the cream and powdered sugar together until somewhat stiff peaks form. Whip the chilled pastry cream to break it up and smooth it out Add half a cup of the whipped cream to the pastry cream then whisk together. Fold in the remaining whipped cream then transfer to a piping bag fitted with a large rough tip like a 1a or 803. You DON'T have to add whipped cream to your pastry cream but it does lighten things up and increase the volume of your filling.
3. Pipe 8 dollops of pastry cream onto the first piece of puff pastry. Place another piece of pastry on top then pipe eight more dollops and add the top on.