I need Help!!! I have a wedding cake in a few months and the bride is wanting chocolate Hazelnut Mousse for the filling and I can't find a receipe for it, can someone please help??????

I made a filling for my MIL's birthday cake using Nutella. If I remember correctly I used 8oz cream cheese, 1 jar of Nutella (13oz), 1/2 c of whipping/heavy cream and powdered sugar to taste. I don't remember how much sugar I used. Everyone loved it. I couldn't find a recipe so I put this one together and everyone loved it.