Preheat your oven to 375°F (190°C) and lightly grease a medium-sized oven-safe baking dish with the coconut oil.
In a large mixing bowl, whisk together the Greek yogurt, eggs, vanilla extract, sea salt, cinnamon, and maple syrup until the mixture is completely smooth and well-combined.
Gently fold in the rolled oats and half of the fresh blueberries using a spatula to ensure they are evenly distributed throughout the yogurt base.
Pour the mixture into the prepared baking dish, smoothing the top with a spatula to create an even layer.
Scatter the remaining blueberries across the top of the yogurt mixture, pressing them slightly into the surface.
Bake for 25 to 30 minutes until the yogurt is set around the edges and the center has a slight, firm jiggle.
Remove from the oven and let the dish rest for at least 5 to 10 minutes to allow the custard to firm up before serving.