Chill a medium mixing bowl in the refrigerator.
In a medium bowl, beat the egg yolks with an electric mixer at high speed until thick and pale, about 3 minutes. Gradually beat in the sugar until combined.
Warm (not boil) 1 cup of cream in a 2-quart saucepan over medium heat. Slowly stir in half of the cream into the egg yolk mixture. Transfer the cream-egg yolk mixture into the saucepan and stir.
Reduce the heat and stir constantly until thick, about 5 minutes. Do not let the mixture come to a boil.
Add the baking chips and stir until melted. Cover the saucepan and refrigerate for 2 hours, stirring occasionally, until chilled.
Pour 1 ½ cups of the cream into the chilled bowl. Beat with an electric mixer at high speed until stiff peaks form, about 5 minutes.
Using a rubber spatula, gently combine the chilled mixture with the whipped cream, careful not to deflate the cream. Spoon mousse into glasses and garnish with chocolate curls, if using.
Cover the glasses with plastic wrap and refrigerate. Enjoy!
