Both the sauce and ice cream are super chocolately, so if you don't adore dark chocolate, these are not for you, or at least don't make them at the same time.
Hot Fudge Sauce
from Dorie Greenspan
Makes 1 3/4 cups
3/4 cup heavy cream
1/3 cup light corn syrup
1/3 cup light brown sugar
1/4 cup unsweetened cocoa powder
1/4 tsp salt
6 ounces semisweet chocolate, very finely chopped
3 tablespoons butter, cut into bits
1 teaspoon pure vanilla extract
Bring the cream, corn syrup, sugar, cocoa and salt to a boil over medium heat. Lower the heat and simmer, stirring occasionally, for 3 minutes. Off heat, stir in the chocolate and butter. Return to a simmer for 1 minute more, then stir in the vanilla. Pour into a heatproof jar and use now or cool, cover tightly, chill and reheat very, very gently before serving.
Chocolate Ganache Ice Cream
from Baking: From My Home to Yours by Dorie Greenspan
6 ounces bittersweet chocolate, finely chopped
1 ½ cups heavy cream
1 cup whole milk
4 large egg yolks
1/3 cup sugar
Put the chocolate in a 2-quart liquid measuring cup or a large heatproof bowl. Bring ¾ cup of the cream to a boil. Pour the cream over the chocolate and let it sit a minute, then using a rubber spatula and starting in the center of the mixture, slowly stir the cream into the chocolate in ever-widening concentric circles. When the ganache is smooth, set it aside.
Bring the milk and the remaining ¾ cup cream to a boil in a medium heavy-bottomed saucepan.
Meanwhile, in a medium bowl, whisk the yolks and sugar together until well blended and just slightly thickened. Still whisking, drizzle in about one third of the hot liquid—this will temper, or warm, the yolks so they won’t curdle. Whisking all the while, slowly pour in the remaining liquid. Pour the custard back into the pan and cook over medium heat, stirring without stopping, until the custard thickens slightly and coats the back of a spoon; if you run your finger down the bowl of the spoon, the custard should not run into the track. The custard should reach at least 170 degrees F, but no more than 180 degrees F, on an instant-read thermometer. Immediately remove the pan from the heat and slowly and gently stir the custard into the ganache.
Refrigerate the custard until chilled before churning it into ice cream.
Scrape the chilled custard into the bowl of an ice cream maker and churn according to the manufacturer’s instructions. Pack the ice cream into the container and freeze it for at least 2 hours, until it is firm enough to scoop. Makes about 1 quart.
Serving: If the ice cream is very firm—as ice cream made with premium-quality chocolate often is—allow it to sit on the counter for a few minutes before scooping or warm it in a microwave oven using 5-second spurts of heat.
Storing: Packed tightly in a covered container, the ice cream will keep in the freezer for about 2 weeks.