This doesn't keep very well... you need to use it almost immediately or it will separate:
1 Tbsp unflavored gelatin (1 packet)
1/4 cup cold water
1 1/2 cups 1% milk
1/4 cup Splenda
1 tsp pure vanilla extract
In a small bowl, sprinkle the packet of unflavored gelatin over the cold water and let stand until the gelatin absorbs the water.
In a medium saucepan over medium-low heat, scald the milk.
Remove from the heat and add it to the gelatin, whisking until the gelatin dissolves.
Stir in the Splenda and vanilla extract.
Refrigerate, stirring every ten minutes, until very cold (about 1 1/2 hours) and then place in a large bowl of ice water for 30 minutes, and let it stand, whisking often.
Using a handheld mixer set at high speed, beat until the mixture is thick and fluffy.
Splenda is an artificial sweetener here in the U.S. made from sucralose(Source: Splenda International)