Preheat oven to 350°.
To prepare crostini, place bread slices on a large baking sheet; brush with 1 tablespoon olive oil. Bake at 350° for 15 minutes or until lightly browned.
To prepare cioppino, heat 2 teaspoons oil in a Dutch oven over medium-high heat. Add crushed red pepper and garlic; sauté 30 seconds. Stir in clam juice and next 5 ingredients (clam juice through pasta sauce.) Add clams and mussels. Cover and cook 10 minutes or until shells open. (Discard any unopened shells.) Add wine and next 4 ingredients (wine through shrimp); simmer 5 minutes or until fish and shrimp are done. Stir in spinach. Serve with the crostini.