To soften cream cheese, simply let it sit on the counter in the original foil package for 30 minutes before using it.
Beat cream cheese, whipped topping, and cake mix on medium-high speed for about 2 minutes, until smooth and fluffy. (Note: start beating on low speed until cake mix is incorporated so it doesn't poof in your face.)
Add hot fudge topping and heavy whipping cream and beat for another minute or so until all smooth.
Fold in mini chocolate chips if using.
Serve right away or refrigerate in an air-tight container.
To Heat-Treat Cake Mix:
Place the mix into a microwave-safe bowl but add some extra in case some parts get overheated. Heat it in a microwave on high power in 30 second increments and stir well in between each interval. Use an instant read thermometer to make sure the flour mix reaches 165°. Discard any parts that may have gotten singed. Cool flour mix down first, before using it in the recipe!