Preheat oven to 350 F. Grease your 12 inch cast iron skillet or a similar capacity baking dish (I used coconut oil). In a large bowl combine all of your wet ingredients (eggs through milk). In another bowl combine all of your dry ingredients (oats through cinnamon). Pour your dry ingredients into your wet ingredients and mix. Pour this batter into your pan or dish. Now you can place your blueberries on top now and bake them into the oats if you prefer them cooked, or wait, like I did and place them on after the cake is done, as a topping.
Bake for about 30 minutes (I do the toothpick test). Once it is baked, remove from oven, allow to cool a bit and then add your toppings (blueberries, whipped cream and/or coconut flakes).