In a mixing bowl, whisk together the all-purpose flour, protein powder, sugar, baking powder, and salt. In another bowl, combine the milk, eggs, vanilla extract, and melted butter. Whisk until well blended. Gradually add the wet ingredients to the dry ingredients, stirring gently. Let the batter rest for about 10 minutes.
Heat a non-stick skillet over medium heat and lightly grease it with butter. Pour about 1/4 cup of the batter into the skillet. Cook the crepe for 1-2 minutes, or until the edges start to lift and the bottom is lightly browned. Flip the crepe and cook the other side for another 1-2 minutes. Repeat with remaining batter.
In a small bowl, mix the softened cream cheese, powdered sugar, cinnamon, and milk until smooth. Take one crepe, spread a thin layer of the cream cheese filling over it, roll it up tightly, and place it on a serving plate. Repeat for each crepe.