Preheat your oven to 425°F and line 2 muffin tins with liners, skipping every other one.
In a large mixing bowl, whisk together melted coconut oil, monk fruit sweetener, eggs, vanilla extract, and oat milk until well combined.
Sift in the all-purpose flour, baking soda, baking powder, salt, and cinnamon.
Before mixing, gently fold the blueberries into the flour until just combined.
Sprinkle turbinado sugar on top of the muffins, if desired.
Bake at 425°F for 15 minutes, then reduce the heat to 375°F and bake for another 10 minutes without opening the oven door.
Let the muffins cool slightly before enjoying warm!