Place chocolate, water, and Kirschwasser in a medium size heatproof bowl. Bring 1 inch of water to a simmer in a wide skillet. Turn the heat off and wait 30 seconds. Set bowl of chocolate in pan of water. Stir white chocolate mixture constantly until melted and smooth. Or, melt in a microwave on low for about 2 minutes. Stir until smooth and completely melted. White chocolate is very fragile and burns easily. Do not turn the heat on again under the skillet unless absolutely necessary. Let cool until a dab touched by your upper lip feels slightly cool. Whip the cream until soft peaks form--not too stiff. Carefully fold cream into cooled white chocolate mixture; the mousse will seem very soft. Scrape mold immediately into lined mold. Mousse sets quickly and should not be spread or manipulated too much after it is completed.