Bring milk and half the cream to a boil in a medium pan over medium heat, whisking constantly. When milk is simmering, stir in the chocolate, powdered sugar and cocoa. Stir until chocolate has melted. Pour a tablespoon of amaretto into 4 warmed glasses. Pour the chocolate mixture over the top, scooping in the froth. Beat the remaining cream until soft peaks hold. Spoon over chocolate drinks and sprinkle with toasted almonds. Serve at once, garnished with the amaretti cookies.