Now it’s time to make the custard filling. We recommend using a double boiler for this process. A double boiler when you take a larger pan and fill it and enter two with water and bring it to a boil. Then take a smaller pan and place it in the center.
To make the filling, begin by heating the milk in the double boiler until it is scalding. This means that it should reach 185°F but be careful that you do not burn the milk.
While your milk is heating, crack eggs and separate the yolks from the egg whites. Take the egg yolks and beat them until they are mixed.
When the milk is scalding, add the egg yolks slowly to the mixture stirring vigorously.
In a small mixing bowl combine sugar and cornstarch and whisk until combined. Then pour this mixture into your milk and egg mixture. Cook in the double boiler, stirring continually until the mixture thickens and sticks to the back of the spoon. This should take between 10 and 15 minutes.
Add vanilla extract to the custard mixture and mix until combined. Pour half of the custard into a bowl and set aside as it cools.
Please note that you can make as much of this filling chocolate as you want. It is entirely up to you!