Penny's Chocolate Mousse

Preparation

1. 1. Step 1

      Make the mousse: Add the egg yolks to a medium bowl. To stabilize the bowl, place a dampened paper towel or nonslip mat underneath it. To a medium pot, add the heavy cream, milk and corn syrup. Put the chocolate, butter, vanilla extract and salt in a large bowl (if using an immersion blender) or blender bowl, and set aside. 

   2. Step 2

      Over medium heat, scald the cream mixture, whisking occasionally, by heating it to 170 degrees, 5 to 7 minutes. Small bubbles should be forming around the edges of the pot and small wisps of steam rising off the surface, but it should not be boiling. 

   3. Step 3

      Turn off the heat and slowly stream about 1 cup of the cream mixture into the egg yolks, whisking constantly to temper the yolks so they don’t scramble. Add the egg mixture to the pot, whisking constantly. Turn the heat back to medium and cook for 2 to 3 minutes longer, whisking constantly, until the mixture reaches about 170 degrees. It will only be slightly thicker, but this will heat up the egg yolks enough to be safe for consumption.

   4. Step 4

      Slowly pour the warm mixture over the chocolate mixture in the large bowl. Let sit for 2 minutes, then blend until completely smooth with an immersion blender or a stand blender. If using a stand blender, start it on low speed and gradually raise to medium-high, so that it doesn’t erupt all over your kitchen. With the blender running, slowly stream in the oil. Pass the mixture through a fine-mesh sieve into a bowl or other vessel that will fit in your refrigerator, press plastic wrap gently on the surface to reduce condensation, and chill for at least 4 hours, or overnight. 

   5. Step 5

      Make the candied hazelnuts: Heat the oven to 350 degrees. Place the hazelnuts on a rimmed baking sheet and toast for 8 to 10 minutes, or until fragrant but not burnt. While they’re still warm, bundle the hazelnuts in a clean kitchen towel and gently rub the skins off. (It doesn’t have to be perfect; you just want to remove most of the skins.) Coarsely chop the toasted nuts or place them back on the rimmed baking sheet and firmly press them with another rimmed baking sheet to halve them. Let cool while you make the caramel.

   6. Step 6

      Line a large rimmed baking sheet with a silicone baking mat or parchment paper. Set a small bowl of water and a pastry brush near the stove. 

   7. Step 7

      In a medium pot, bring the sugar and 2 tablespoons water to a boil over medium-high. Stir just until the sugar dissolves and the mixture begins to bubble vigorously, 2 to 3 minutes, then stop stirring. Dampen the pastry brush with water and carefully brush down the sides of the pot where errant sugar crystals may have formed so that they don’t burn and the caramel doesn’t crystallize. Swirl the pot occasionally and cook until the caramel is a rich amber color, about 7 minutes. Remove from the heat. Immediately add the hazelnuts and stir with a spatula until they’re evenly coated. Spread them out on the lined baking sheet in an even layer, sprinkle with the salt and let cool until the caramel has hardened, about 20 minutes. Break up the mass into bite-size pieces.

   8. Step 8

      When ready to serve, scoop the mousse into serving bowls. (If you prefer a looser mousse, gently stir it before serving.) Top with the candied hazelnuts.  You can refrigerate any leftover mousse for up to 4 days.