The day before: In a large pan, like a 9 x 13 casserole dish, add the first four ingredients (oats, melted oil, melted honey or sugar, cultured milk). Mix well, so that everything is moist. Cover with a clean kitchen towel and leave it to sit on the counter until the next morning.
The next morning, preheat the oven to 350 F, and then add the last four ingredients (eggs, baking powder, salt, cinnamon). Sometimes it's a bit difficult to mix the oats if it's been chilly during the night. On really cold days I've had to pop the pan back into the oven for a minute while it's preheating, just to soften the butter or coconut oil enough to be able to stir it better.
This is also the time that you could add any fun additions that your family would enjoy. One that we love is grated or diced apples and raisins (with extra cinnamon and some nutmeg). Fresh or frozen (thawed slightly) blueberries are delicious. Chopped nuts is always yummy and ups the protein of this dish (I’ve tried almonds, walnuts and pecans). Other dried fruits like cranberries, cherries or chopped apricots are also lovely. Another option is to add these extras on top, after it’s baked.
When everything is well mixed, smooth it out a bit, and put it in the oven for 40-45 minutes, until lightly browned and crisp on top.