Rocher Style Croissant

Name: Rocher Style Croissant
Prep time: 1 h
Cook time: 6 h
Total time: 7 h
Cuisine: European, Mediterranean, French
Ingredients: 3 cups all-purpose flour; 1 tablespoon instant yeast; 1/2 cup sugar; 1 tablespoon salt; 1 1/2 cups milk; 2 tablespoons butter, cubed; 3 sticks butter, at room temperature; 2 tablespoons all-purpose flour; 1 large egg; 1 cup hazelnut spread; 1/2 cup crispy rice cereal; 1 1/2 cups milk chocolate; 1/2 cup hazelnuts, chopped