Preheat oven to 350° F (175° C). Grease an 11x13-inch baking dish with cooking spray and set aside.
In a large skillet, melt butter over medium-high heat. Add shrimp and scallops to the pan, season with salt and pepper, and cook for 3 minutes until lightly browned. Remove from heat and set aside.
In a large bowl, combine cream, chicken broth, Parmesan cheese, scallions, parsley, basil, dill, and panko breadcrumbs. Mix until all ingredients are well combined.
Add cooked shrimp and scallops to the baking dish. Pour cream mixture overtop and spread out evenly with a rubber spatula. Sprinkle crabmeat on top of the casserole.
Bake in preheated oven for 25-30 minutes until the top is golden brown and bubbly. Serve hot with your favorite side dishes.