Whipped cream inside flourless chocolate cake??
You'll get a mess- the cream won't hold up to heat. Generally filled cakes and pastries are filled after baking.
You should add the cream after the cake comes from the oven. If you want to bake in a filling, try mascarpone instead of whipped cream. That still may run a bit, but it has a chance of holding its shape some.
Or add a frozen chocolate truffle as a filling , won't be too runny when baked
Kinda sorta relevantly, there was a cake I made a few times years ago that used whipped cream as leavening; best I remember, it was folded into the batter, which presumably had enough structure to hold up once it started cooking.
I have a similar recipe for cupcakes that uses a mix of cream cheese, eggs and chocolate chips for the creamy center, with a quick "chocolate whacky-cake" batter. You fill the cupcake tins, then put in a spoonful of the cream cheese mixture before baking. Delicious.
A little boy, that I used to give riding lessons to in England, brought me a box of these on his last day before I came home. His mom gave me the recipe and I still make them a couple times a year. Nice memories. :)