For the Crème Anglaise Sauce

Step 1

• Scald the milk and cream with the vanilla in a heavy saucepan, remove from heat, and set aside.

Step 2

• In a small bowl, whisk together the egg yolks, sugar, and liqueur or orange peel. Add about ⅓ cup of the scalded cream mixture into the bowl, whisking continuously, to temper.

  Slowly pour this mixture into the saucepan, whisking continuously, until fully incorporated with the remaining milk mixture. Heat the mixture over medium heat, continuing to whisk, until the mixture has thickened. It will thickly coat the back of a spoon when ready.
  

Step 3

• Pour the mixture through a fine-mesh strainer into a small bowl, and allow to cool for 10 minutes, stirring occasionally. Cover with plastic wrap, and refrigerate until ready to use. The mixture should be fully chilled.
  

For the Chocolate Soufflé

Step 1

• In a heavy saucepan over low heat, begin to melt the chocolate with 3 tablespoons (45g) butter, stirring periodically with a wooden spoon or rubber spatula (you may also do this in a double boiler). Watch carefully to ensure that the chocolate does not burn.
  

Step 2

• While waiting for the chocolate to melt, preheat your oven to 400°F (200°C). Do not use the convection setting. Place six 8oz (235mL) soufflé molds or one 1 ½ quart (1400mL) soufflé mold atop a lined sheet pan.

Step 3

• Generously butter the molds with 2-3 tablespoons unsalted butter, and sprinkle the interior with granulated sugar. Turn each mold upside down and tap gently to remove any excess sugar, and return to the sheet pan. 
  

Step 4

• Once the butter has melted, whisk in the cocoa powder, salt, and espresso powder, being sure to break up any lumps, and remove from the heat. 

Step 5

• Whisk the egg yolks together in a small bowl and, whisking continuously, add a large spoonful of the chocolate mixture to temper until well-combined.

  Return the yolk mixture to the remaining chocolate mixture in the saucepan, continuing to whisk. Set this mixture in the refrigerator to cool for a few moments while you move on to the next step.

Step 6

• Add the egg whites to a large, clean, mixing bowl, ideally the bowl of a stand mixer fitted with the balloon whisk attachment (a large bowl and hand mixer will do). Add the cream of tartar, and beat until soft peaks form. While continuing to beat, add the remaining sugar and beat until the egg whites are glossy and form stiff peaks when the whisk is removed. 
  

Step 7

• Remove the chocolate mixture from the refrigerator, and stir a few times with a rubber spatula to loosen.

  Gently fold one-third of the egg whites into the soufflé base to lighten, then continue to gently fold in the remaining egg whites until no white streaks remain. If the mixture is not well-combined, it will cause your soufflé to rise unevenly and crack. 
  

Step 8

• Scrape the mixture into the prepared ramekins. The mixture should almost reach the bottom part of the rim. 

  Place the soufflés in the middle rack of the oven, shut the door, and immediately turn the temperature down to 375°F (190°C). Do not open the oven during the cooking process. Bake for 12-14 minutes (less for small, individual molds; more for one large soufflé).
  

Step 9

• While the soufflé is baking, transfer the cold crème anglaise sauce into a small pitcher (a coffee creamer pitcher is ideal) and place it at the serving table.

Step 10

• When the soufflé has risen well above the mold of the rim, you may test it by slightly jiggling the sheet pan. The soufflés should have a very slight wobble. If you poke with the needle of a kitchen thermometer or long wooden tester, it should come out slightly wet, but not dripping with batter. If it comes out quite wet, continue to bake for another 2-3 minutes. 
  

Step 11

• Bring the soufflés to the serving table immediately once they have been removed from the oven. Dramatically pierce the soufflé with a knife, tearing a large, deep slit into its center, and pour in the accompanying sauce, to the delight of your lucky guests.