1. In a saucepan mix sugar and cocoa. Add milk, cream, yolks and chocolate. Whisk over medium-high heat until chocolate is melted and mixture just starts to bubble. Add vanilla and strain through a fine sieve.
2. Stir mixture over an ice bath until cold or chill overnight. Churn in an ice-cream maker; keep frozen in an airtight container for up to a month.
1. Mix 2 teaspoons finely grated orange zest and 4 ounces chopped white chocolate into 1 quart chocolate ice cream
1. Stir 1 cup mini marshmallows and 1 cup crumbled graham crackers into 1 quart chocolate ice cream.
1. Deeply roast 1 cup almonds. Cool, coarsely chop, and stir into 1 quart chocolate ice cream. Swirl in 1/3 cup warm fudge sauce.
1. Mix 1 cup chopped banana, 1/2 cup chopped toasted walnuts, and 1/2 cup chopped maraschino cherries into 1 quart chocolate ice cream.
1. Mix 1/3 cup toasted unsweetened coconut into 1 quart chocolate ice cream. While stirring, drizzle in 2 ounces melted semisweet chocolate.
1. Stir 1 1/4 cups coarsely chopped malted milk balls into 1 quart chocolate ice cream.