Make the filling: Beat the brown sugar and butter together in a bowl with an electric mixer until fluffy. Beat in the vanilla extract. Add the flour and salt and mix until combined. Add cream a little at a time until the mixture is spreading consistency (you may not have to use all of the cream). Fold in chocolate chips. Place a cake layer on a serving plate or cake stand. Cover the layer with half of the cookie dough frosting and top with a second cake layer. Cover the second layer with the remaining frosting. Place the remaining cake layer on top