1. Beat the butter until light and creamy, then gradually add the powdered sugar until the frosting is light and fluffy. Beat in the vanilla and pomegranate molasses.
2. To frost a cake, cut the cake in half horizontally, and place the bottom on a cake plate. Spread one-fourth of the frosting over the cake and sprinkle with half the pomegranate seeds. Top with the other cake half and frost the top and sides of the cake with the remaining frosting. Sprinkle the cake with the chopped nuts and the remaining pomegranate seeds.