Add the Rao’s Homemade® Marinara Sauce to a blender along with the water and blend on medium speed until smooth.
Transfer the mixture to a medium-sized pot and pour in the cream. Cook over low to medium heat until warmed. Finish with salt and pepper.
Add the butter to a large griddle or frying pan over low to medium heat and place down the 8 slices of bread.
Cook until browned, about 2 to 3 minutes.
Flip the bread over and place 1 slice each of cheddar, provolone, mozzarella, and prosciutto onto 4 pieces of bread. Cook on low heat for 2 to 3 minutes.
Place the 4 slices of toasted bread with no cheese onto the bread with the cheese, making 4 grilled cheese sandwiches.
Cook until the cheese is melted. Slice and serve alongside of the creamy tomato soup.