To freeze: Let the oatmeal cool completely and then cut or scoop into portions. Store the oatmeal in airtight freezer bags or containers. Reheat in the microwave for 30-45 seconds when needed with a tablespoon of water.
Make ahead: Combine all ingredients as directed. When ready to bake, give mixture a quick stir, dump into greased pan, and bake as directed, adding an extra 5-10 minutes to baking time.
Gluten free: make sure your oats are labelled as certified gluten free.