Line an 8-by-8-inch pan or baking dish with Reynolds Wrap® Heavy Duty Foil, then set aside.
Combine the confectioners’ sugar, butter, cream cheese, cocoa powder and vanilla in a mixing bowl.
Stir together on low speed until the dry ingredients start to blend with the butter and cream cheese.
Increase the speed and whip for about 30–60 seconds at high speed to make sure all of the ingredients are blended well.
Fold in your choice of mix-ins if using.
Spread out into the prepared pan.
Cover and refrigerate until firm, about 25–30 minutes.
Remove from the pan by lifting it up by the foil and slice into 1-inch squares using a sharp knife.
Transfer to a serving tray before the fudge warms and softens, or cover with Reynolds Wrap® Heavy Duty Foil for storage.
Keep refrigerated when it is not being enjoyed.