In a small saucepan, combine the mixed berries, lemon juice, and water over medium heat.
Simmer the mixture for 5-7 minutes, stirring occasionally, until the berries break down into a thick, bubbling sauce.
In a large mixing bowl, whisk together the oat flour, baking powder, and sea salt until well combined.
Add the egg whites, non-fat Greek yogurt, and vanilla extract to the dry ingredients, stirring until a smooth batter forms.
Lightly coat a large non-stick skillet with coconut oil and place it over medium-low heat.
Portion the batter by 1/4 cup scoops onto the skillet, ensuring enough space between each pancake.
Cook for 3-4 minutes until bubbles form on the surface, then flip and cook for another 2 minutes until golden brown.
Serve the warm pancakes immediately, topped generously with the fresh berry compote.