Step 1

In a large bowl, whisk together egg yolks and sugar for about 1 minute, just until lightened in color and velvety.

Step 2

In a small saucepan, heat 1¼ cups of cream over medium heat just until it's steaming, about 4 minutes. Remove from the heat.

Step 3

Add the chocolate and stir constantly until fully melted. Slowly whisk chocolate into the egg yolks until fully combined. Set aside to cool, stirring occasionally, until barely warm to the touch, about 30 minutes.

Step 4

In another large bowl, beat the egg whites until stiff peaks form. Fold a third of the egg white mixture into the chocolate mixture to loosen it. Fold the remaining egg white mixture in just until a few streaks remain.

Step 5

In a large bowl, beat the remaining 1 cup of cream until stiff peaks form. Fold whipped cream into the chocolate mixture. Fill 6 to 8 small serving glasses with the mousse.

Step 6

Chill until set, about 4 hours or up to 2 days. (If chilling for more than a few hours before serving, loosely cover the mousse to keep it from forming a skin and drying out.) Serve topped with whipped cream and chocolate shavings, if desired.