Dissolve unflavored gelatin in cold water. Cream sugar and egg yolks. Slowly pour the boiling milk over egg mixture. Pour in saucepan. Stir with a wooden spoon over low heat until the mixture coats the back of the spoon. Do not allow to boil. Dissolve the instant coffee in the boiling water. Stir in the gelatin and coffee in custard. Strain into a bowl. Cool mixture.
Whip the heavy cream to a medium peak. Fold in the cool custard. Pour in a decorative mold. Refrigerate for 2 hours or longer.
To unmold:
dip mold in hot water for a few seconds. Invert onto a serving platter. Serve cold.