Add egg yolks to a stand mixer with the whisk attachment. On the highest speed whisk yolks until they thicken. Takes about 3-4 minutes.
Meanwhile, heat ½ cup heavy cream in a medium saucepan. Do not boil just warm up the cream.
Add a splash of the warm cream to the egg mixture and stir gently. We are shocking the eggs so they do not get too hot and scramble.
Next add the egg mixture with the rest of the cream into the sauce pan.
Cook mixture until thick, 2 minutes.
Add in chocolate and stir until melted and take off of the heat.
Meanwhile, add the remaining ½ cup of heavy cream to the stand mixer with the whisk attachment. Whisk until cream forms soft peaks. Very carefully fold the whipped heavy cream into the chocolate mixture. Place in the refrigerator until ready to assemble S’mores Mousse.