I stumbled on this recipe when my standard White Chocolate Mousse filling I made for an upcoming cake was a major FAIL yesterday (not sure what happened, but it was super grainy and lumpy - not good). I had all the ingredients on hand for this one so tried it out and was REALLY impressed with how quick, easy and tasty it was. I know it's not officially a "mousse" since there are no eggs involved, but it's light and fluffy like a mousse. The original recipe called for 1/2 cup of sour cream (which I didn't have), so I substituted 3 oz. of cream cheese and it worked like a charm.
3 oz. cream cheese
1 pkg (3.3 oz.) instant white chocolate pudding mix
1 Cup heavy cream
1/4 cup milk
1/4 cup powdered sugar
Beat softened cream cheese with electric mixer until fluffy. Add all other ingredients and beat until stiff peaks form. It comes together REALLY quickly! Refrigerate for a few hours until completely set.