Melt the Chocolate: In a microwave-safe bowl, heat 1/2 of the heavy cream for about 1 minute. Stir in 1 cup of chocolate chips until combined, then let the mixture rest for 5 minutes so the chocolate can fully melt.
Cool the Mixture: Whisk the chocolate and heavy cream until it is smooth, and then set it aside to cool while you whip the remaining cream.
Whip the Cream: In a medium bowl, pour the remaining 1 cup of cold heavy cream. Using a hand mixer, stand mixer, or whisk, beat the cream until soft peaks form. Scoop out 1/2 cup of this whipped cream into a small bowl, cover, and refrigerate (you’ll use this later to top the mousse). Continue whipping the rest of the cream until stiff peaks form.
Fold Everything Together: Using a large spatula, gently fold the whipped cream into the cooled chocolate mixture in three batches. Work quickly and don’t worry if you see small streaks of cream in the mousse. Fold in powdered sugar and vanilla extract.
Chill and Serve: Divide the mousse among 4 small ramekins or glasses. Refrigerate for at least 1 hour (up to 4 hours). To serve, dollop with the reserved whipped cream and top with grated chocolate or chocolate curls.
Notes
What type of chocolate to use?CHOCOLATE CHIPS: The pros of using chocolate chips is that they are widely available and come in milk, semi-sweet, and dark chocolate. The cons would be that they have stabilizers to help keep their shape that can slightly affect melting.CHOCOLATE BARS: The pros are often a higher quality cocoa content, pure chocolate flavor, and fewer stabilizers so it melts easier and is smoother. The cons would be that chocolate bars could be more expensive than chocolate chips.My favorite brands of chocolate are Guittard, Ghiardelli, Valhrona, and Callebaut. I also buy the Pound Plus Bars at Trader Joe's. Read the blog post for more detailed information including FAQ's. Recipe adapted from the Kitchn. Added powdered sugar and vanilla extract to the recipe.