While the milk mixture heats, whisk together the egg yolks and additional 2 tbs. sugar in a small bowl. When the milk mixture is steaming, slowly pour about half of the mixture into the egg yolks while whisking constantly. pour the entire mixture back into the pan, and whisk over medium heat until it becomes very thick. This should take about 5 minutes. The custard will be very thick at this stage, and that's ok! Pour the custard into a heat safe bowl, and cover it by placing plastic wrap directly onto the custard to prevent a skin from forming. Let the custard chill fully, about 2 hours in the fridge.