If you have any leftovers, store the clafoutis in an airtight container for three to four days. Since it’s a custard-based dessert, we definitely want to keep it refrigerated. To reheat, you can microwave it in short intervals until it’s heated to your liking. Alternatively, you can cover it in foil and reheat in the oven just until warm, about five to 10 minutes. If you reheat in the oven, let it sit at room temperature for 30 minutes first, especially if you opted to bake it in a ceramic or glass dish. A hot oven can crack a cold baking dish.