These can also be made ahead and frozen—yup, just like the ones you used to get at the grocery store! After baking, let them cool completely and transfer to an airtight container or resealable plastic bag. Store in the freezer for up to 4 months. To reheat in the microwave, simply arrange on a microwave-safe plate and heat for 30 to 60 seconds, until heated through. To reheat in the oven, arrange on a parchment-lined sheet pan and bake at 350°F (175°C, or gas mark 4) for 12 minutes, or until warmed through.