1 1/3 cups whole milk
The hot chocolate mixture can be made 1 day ahead, cooled, covered, and refrigerated. Cover and rewarm over medium-low heat before serving. The whipped cream can be made 2 hours ahead, covered and refrigerated.
In a medium heavy saucepan, combine the milk, amaretto and sugar and bring to a near simmer over medium heat, stirring until the sugar dissolves
While the milk is heating, place the chopped chocolate in a metal bowl and set the bowl over the saucepan of milk, stirring until the chocolate is melted and smooth. Check every now and then to make sure the milk is not simmering
Whisk the melted chocolate into the hot milk mixture and keep warm.
Pour the hot chocolate mixture over the ice cream and top with the whipped cream.
Serve immediately with spoons.