Place chocolate in a medium bowl, and microwave in 30 second increments stirring between each until it’s mostly melted. Or, melt chocolate in a double boiler. Stir chocolate until completely melted and smooth. Set melted chocolate aside; let cool slightly.
7 ounces dark chocolate
Whisk milk and cocoa powder in a medium heavy saucepan over medium heat until mixture begins to boil; set aside.
2 cups plus 2 tablespoons whole milk, 1/3 cup unsweetened cocoa powder
Using an electric mixer, beat egg yolks and 7 tablespoons sugar in another medium bowl until very thick ribbons form, about 2 minutes. Whisking constantly, gradually add hot milk mixture to egg yolk mixture. Return mixture to saucepan. Add melted chocolate and whisk to blend. Stir over low heat until slightly thickened and an instant-read thermometer registers 175°, about 5 minutes. Transfer chocolate custard to a large bowl and place over another large bowl of ice water. Stir until chocolate custard is cool.
6 large egg yolks, 13 tablespoons sugar
Bring remaining 6 tablespoons sugar and 2 tablespoons water to a boil in a small heavy, deep saucepan over medium-high heat, stirring until sugar dissolves. Boil, occasionally swirling pan and brushing down sides with a wet pastry brush (do not stir), until a dark amber color forms, about 5 minutes. Gradually whisk in cream (mixture will bubble vigorously). Whisk caramel into chocolate custard. Strain into a large container; cover and chill for at least 4 hours or overnight.
13 tablespoons sugar, ¼ cup heavy whipping cream
Process custard in an ice cream machine according to manufacturer's instructions, adding toasted almonds in the last minute of mixing. Transfer to another container; freeze before eating.