If you are whipping up some cream to serve immediately on your holiday pie, all you need is a little sweetener. But If you want to whip that cream up ahead of time and have it hold its shape for a while, adding a little stabilizer will help accomplish that end result. The most popular additives to stabilize whipped cream are gelatin and cornstarch. Gelatin will provide a lot of strength and will help that whipped cream hold its shape for up to 3 days in the fridge! Cornstarch is similar, but what I like is the fact that all powdered sugar contains a small amount of cornstarch in it. And since we need to add sweetener to make the mousse, we might as well make it powdered and stabilize while we sweeten! This is how we accomplish a perfectly thick 3 ingredient chocolate mousse!