Place the butter, chocolate, and amaretto (or water) in a small bowl and microwave in 15 second intervals, stirring, until melted and smooth. Set aside to cool.
Place the egg yolks, sugar, and water in a medium mixing bowl and place over a small pot of barely simmering water.
Cook, whisking, until pale and airy.
Remove from the heat and and continue whisking on medium-high speed until cooled.
Fold in the chocolate mixture.
In a large mixing bowl, whip the egg whites and salt until stiff.
Stir in the extract and fold in the chocolate mixture.
Transfer to 4-ounce serving dishes, and chill.