In the bowl of an electric mixer fitted with the whisk attachment, lightly beat 1 1/2 cups heavy cream until whipped; set aside.
In the clean bowl of an electric mixer fitted with the whisk attachment, beat egg yolks until fluffy, 8 to 10 minutes.
Meanwhile, in a small saucepan, bring remaining 1/2 cup cream and sugar to a boil over medium-high heat, stirring to dissolve sugar. With the mixer running, add hot cream mixture to egg yolks in a slow, steady stream.
Gently fold in chocolate and whipped cream. Cover and keep refrigerated until ready to use.