Blend the oats and erythritol into a fine powder.
Add the instant coffee, cocoa powders, salt, and baking powder to the blended dry ingredients and mix well.
Beat the egg whites until stiff peaks form.
In a separate bowl, mix the Greek yogurt, almond milk, and vanilla extract.
Fold the egg whites and yogurt mixture into the dry ingredients until a thick batter forms.
Pour the batter into a 9x9 inch baking pan lined with parchment paper.
Bake at 375°F for 18 minutes.
Allow the brownies to cool, then cut into 16 pieces.
