Chocolate St. Honoré Cake

Instructions

1. Preheat the oven to 425°.  Line two baking sheets with parchment paper.
2. Transfer the thawed pastry sheets onto the baking sheets and cut out two 9" circles with a knife.  Refreeze the scraps for future use.  Pierce the puff pastry circles all over with a fork to prevent air pockets and set aside.
3. To make the pate a choux:  In a medium saucepan over medium heat, combine the water, butter and salt, and stir until the butter is melted and the mixture comes to a simmer.  Add the flour all at once and continue cooking and stirring until a dough ball forms (30 seconds to 1 minute). 
4. Transfer the dough into a mixing bowl and let cool for about 10-15 minutes until just warm to the touch.  After cooled, add the eggs, one at a time and mix well between additions, scraping down the sides of the bowl if needed.  Transfer the sticky dough into a pastry bag tipped with a large, round tip.
5. Pipe the dough over the unbaked puff pastry, creating three concentric rings.  With the remaining dough, pipe out 1 to 1 ½" dollops for the profiteroles.  Wet the tips of your fingers and smooth down the top of the dollops slightly.
6. Move your oven racks to middle and mid-upper levels if needed.  Bake the layers at 425° for 10 minutes.  Switch the pans to the opposite level, turning the pan front to back as you do. 
7. Reduce heat to 350° and bake for an additional 35 minutes, until the pastry is golden brown.  Remove from oven and use a small filling tip (or chop stick) to punch a little hole in the bottom of each profiterole. Cool completely, approximately 30 minutes. 
8. For the custard:  In a medium bowl, whisk together the egg yolks and sugar until thick and pale.  In a small cup, combine the cornstarch and water to create a smooth slurry and add it to the egg yolk mixture and set aside.  In a medium saucepan, whisk together the milk and flour.  Cook over medium heat, stirring constantly, until steaming hot.
9. Temper the hot milk into the egg yolk mixture by drizzling the milk in very slowly while constantly briskly whisking.  Pour the mixture back into the saucepan and cook over medium heat, stirring constantly, until the mixture thickens into a custard, 4-6 minutes. 
10. Remove the custard from the heat, and whisk in the chocolate and butter until smooth.  Pour into a medium bowl and cover with plastic wrap, then cool in the refrigerator for 30 minutes.  Once the custard has cooled, transfer it into a pastry bag and fill each profiterole.  Melt the chocolate melts and dip the tops of each profiterole in the chocolate, then place on a rack to set.
11. In a small bowl, whisk together the softened cheese* and cognac for 1 minute until creamy.  In a mixing bowl, combine the chilled heavy cream and sugar.  Using the whisk attachment, whisk the cream on high speed for 2-3 minutes, until soft peaks form.  Add the cheese and whisk again until creamy and stiff peaks form (45 seconds to 1 minute).  Transfer the whipped cream into a pastry bag tipped with a star tip.
12. Generously pipe dollops of cream on the outer rim and between the outer and 2nd ring of the layer you'll use as the bottom layer.  Then, fill the center with a generous amount of chocolate custard.  Place the top layer on top of the other and finish off with rings and dollops of whipped cream and the chocolate custard.   Top with profiteroles if desired and drizzle with any leftover melted chocolate.
13. Store in the refrigerator if you have any leftover.