Whisk together oat flour, protein powder, baking powder, and cinnamon in a medium mixing bowl.

In a separate bowl, combine Greek yogurt, egg whites, and vanilla extract until smooth.

Fold the wet ingredients into the dry ingredients, stirring until just combined; add almond milk one tablespoon at a time if the batter is too thick.

Preheat a non-stick griddle over medium-low heat and lightly coat with cooking spray.

Pour 0.25 cup of batter per pancake onto the griddle.

Cook until bubbles form on the surface and edges are set, approximately 2 to 3 minutes.

Flip and cook the other side until golden brown, about 1 to 2 minutes.