Clams Casino will freeze very nicely. After stuffing them, place the sheet pan in the freezer allowing the clams to freeze. After the clams casino have frozen solid place them in a container or ziplock bag for storage. The clams casino will hold up frozen for 4-6 weeks. **Cooking the frozen clams won't take too much longer. Place them in a 375- degree oven for 20-25 minutes or until they are bubbly and nicely browned.