Preheat your oven to 350ºF and line a standard muffin tin with 6 baking cups. Create a "chia egg" by stirring together the ground chia seeds and 3 tablespoons of water. Allow the mixture to sit for 5 minutes, until slightly thickened and gel-like, the add in the rest of the ingredients and stir well to combine. Divide the batter among the 6 cups then bake until firm and lightly golden, about 20 minutes.
Serve warm, or allow the oatmeal cups to cool and then store in an airtight container in your fridge for up to one week. We eat them cold straight from the fridge!