Pour you heavy cream into your mixing bowl. Start beating on low. Turn up the speed as it starts to thicken.
After a few minutes when it isn't finished but has thickened slightly, add your sweetener. You can add your vanilla, but I always wait until it is almost perfect.
Keep beating the heavy cream. Turn up the mixer as needed. Add in your vanilla and beat into the heave cream.
Scrape the edges and beat until it is thick. Store in a covered container in the fridge.