Sprinkle gelatin over cold water in 1 1/2 quart mixing bowl.
Heat evaporated milk over very low heat or in the top part of a double boiler placed over hot water.
When milk is hot but not boiling, add all of it, including thin skin which forms on top, to the mixing bowl.
Stir well to dissolve gelatin, then chill thoroughly in freezer for a few minutes.
Whip cold mixture with beater at medium speed until it stands in peaks but is not dry.
Add vanilla and sweetener and beat just long enough to incorporate them.
Put mixing bowl into freezer until mixture is almost frozen, 30-40 minutes.
Divide into 4 equal portions and use at once or store frozen cream mixture, in 4 small bowls or in ice cube tray (without dividers), and use as desired.
Let ice cream soften slightly in the refrigerator before serving.