With 2 sharp knives, cut in 4 T. of firm coconut oil until the mix forms small balls of oil and oats.
Add in cinnamon, mix.
Add in coconut flakes, mix.
Add in walnut pieces, mix, then set aside bowl.
Spread blueberries across the bottom of a Pyrex dish.
Mix lemon extract with the blueberries (to taste, add more if you like lemon flavor).
Spread oatmeal mix evenly over the top of the blueberries.
Drizzle the remainder of the melted coconut oil over the oatmeal topping.
Place tin foil over the dish and bake in the oven for 30 minutes.
Remove tin foil from the dish and bake in the oven for another 10 minutes or so until top is a little golden. (Note: If desired, spritz some coconut oil spray over the top of the dish for more moisture).
After removing the dish from the oven, with a spoon, blend the blueberries with the oat mixture and cover the dish with tin foil. Chill dish in the fridge for a few hours or overnight.
Notes
After chilling in the fridge for a few hours (or overnight), serve this dish hot or cold, on its own, or with your favorite topping (coconut milk ice cream, whip cream, or other).