Preheat your oven to 375°F (190°C).
Heat the extra virgin olive oil in an oven-safe skillet over medium heat.
Add the sliced mushrooms to the skillet and sauté until they release their moisture and become golden brown.
Add the baby spinach to the mushrooms and stir until the leaves are just wilted.
In a medium bowl, whisk together the whole eggs, egg whites, nutritional yeast, sea salt, and black pepper until well combined.
Pour the egg mixture over the sautéed vegetables in the skillet, ensuring they are evenly distributed.
Transfer the skillet to the preheated oven and bake for 12 to 15 minutes, or until the eggs are set and slightly puffy.
While the eggs are baking, cook the rolled oats with one cup of water in a small saucepan over medium heat until the liquid is absorbed.
Serve the baked egg frittata warm alongside the oatmeal topped with fresh blueberries.