Preheat oven to 350°F. Lightly grease a 8 inch square pan.
Add milk, chopped peaches, and dates into a food processor/blender and blend until smooth.
Add all the ingredients (minus sliced peaches) into the baking dish and stir well to combine.
Add sliced peaches on top and bake until the liquid is absorbed, about 30-35 minutes. Wait for at least 20 minutes before slicing. The oatmeal will firm up as it cools.
Notes
Soak dates in hot water so that they will blend easily. Be sure to discard the pits and water.
Make ahead: If you want to prep ahead of time all the way up to baking - Add all the ingredients into the baking pan minus the peach milk. Store it separately and pour the milk over the mixture when you are ready to bake.
Storage: Slice leftover baked oatmeal into individual portions and store in an airtight container for 4-5 days in the refrigerator. To freeze, cut into desired portions, wrap in plastic wrap, and place in a freezer-safe bag. It will be good for up to 3 months.