Preheat oven to 350 degrees Fahrenheit.

Using a beater, mix the butter with the sugars and salt.

Add the eggs, flour and baking soda.

Add the chopped chocolates (and optional walnuts).

Spread the dough in a 12- by 16-inch pan lined with Gefen Parchment Paper. Bake for 20-25 minutes in the preheated oven. While baking, mix the dough with two forks to create crispy crumbs.

Cool slightly and break into smaller crumbs.

In a medium saucepan, boil the milk with the cream and coffee.

In a medium-sized bowl, mix the egg yolks, sugar and cornstarch.

Pour the hot milk mixture over the egg yolks, mix well and return to the saucepan, constantly stirring until the mixture is heated to 185 degrees Fahrenheit. (If you don’t have a thermometer, cook until the mixture softens slightly.)

Strain the hot mixture and pour it onto the chopped chocolate. Combine with an immersion blender until smooth and creamy.

Allow the cream to cool slightly and pour it into the rings or individual molds. Sprinkle generously with the cookie crumbs and transfer to the freezer for four hours. (Any extra crumbs can be frozen for any type of future use.)

Remove the frozen mixture from the molds and return to the freezer.

Serve partially thawed with vanilla ice cream.