In the bowl of a stand mixer fitted with the whisk attachment, beat the cold heavy cream on medium speed for 1-2 minutes, or until soft peaks form. Remove the whipped cream to a bowl and set aside.
1 cup heavy whipping cream
Add the cream cheese and vanilla extract to the mixer bowl (no need to clean it). Mix to combine.
8 ounces cream cheese, 1 teaspoon pure vanilla extract
With the mixer on low speed, slowly add the sifted powdered sugar and cocoa powder until fully incorporated.
¾ cup powdered sugar, ¼ cup unsweetened cocoa powder
Once all of the dry ingredients have been incorporated, turn the mixer to medium-high speed and beat until the mixture becomes lighted, about 2 minutes.
Turn off the mixer and, using a rubber spatula, add half of the whipped cream to the mixture. Fold it in gently – this should be a bit of an arm workout! Once the first batch of whipped cream is fully incorporated, add the remaining whipped cream and fold it into the mousse as well.
Warm the hot fudge sauce according to the package directions just until it is pourable – you don’t want it to be too hot or it will melt your mousse.
½ cup hot fudge sauce
Add a few tablespoons of hot fudge to the bottom of your serving dishes and top with mousse. Garnish with your desired toppings.