Preheat your oven to 375°F and lightly grease a small oven-safe baking dish or large ramekin with a touch of avocado oil or ghee.
Place the rolled oats into a high-speed blender and pulse until they reach the consistency of a fine, sandy flour.
In a medium mixing bowl, whisk together the whole eggs, Greek yogurt, vanilla extract, baking powder, cinnamon, and sea salt until the mixture is completely smooth.
In a separate clean glass or metal bowl, use a hand mixer to beat the liquid egg whites on high speed until stiff, glossy peaks form.
Gently stir the oat flour into the whole egg and yogurt mixture until just combined.
Using a silicone spatula, very gently fold the whipped egg whites into the oat mixture in three batches, being careful not to deflate the air bubbles.
Carefully fold in the fresh blueberries and pour the airy batter into your prepared baking dish.
Bake for 25 to 30 minutes until the soufflé has risen significantly and the top is set and golden brown.
Remove from the oven and serve immediately while the soufflé is at its peak height and warmth.