Mexican chocolate ice cream

Ingredients:

1 cup granulated sugar
Dash of salt
3 cups half-and-half
1 cup heavy cream
4 eggs, beaten
2 teaspoons vanilla extract
3 (1 ounce) squares unsweetened chocolate
1/2 cup granulated sugar
1/2 teaspoon ground cinnamon

Preparation:

Mix the 1 cup sugar, salt and half-and-half in a heavy-bottomed saucepan.
Heat to scalding, stirring occasionally and being careful not to boil.
Slowly whisk about a cup of the hot half-and-half mixture into the eggs, then slowly whisk the egg mixture back into the saucepan.
Cook over medium-low heat, stirring constantly, until the mixture thickens slightly.
Remove from heat and stir in vanilla extract.
Melt the chocolate and 1/2 cup sugar in the top of a double boiler over barely simmering water. Stir until smooth.
Pour the chocolate mixture into the custard. Stir until thoroughly blended.
Stir in the cinnamon. Chill and process in an ice cream freezer.