In a large mixing bowl, combine the all-purpose flour, eggs, milk, melted butter, granulated sugar, and vanilla extract. Whisk until the mixture is completely smooth and well combined. Once mixed, allow the batter to rest for 30 minutes.
Preheat a non-stick skillet or crepe pan over medium heat. Lightly grease the surface with a small pat of butter. For each crepe, pour approximately ¼ cup of the batter into the pan, then immediately swirl the pan to ensure an even coating. Cook for 1-2 minutes, until the edges start to lift and the bottom is light golden brown. Carefully flip the crepe and cook for an additional 1 minute. Transfer the crepe to a plate and repeat with the remaining batter.
In a separate bowl, blend the softened cream cheese until creamy. Gradually add in the powdered sugar, fresh lemon juice, and lemon zest. Mix until smooth and well combined.
To assemble, take one cooked crepe and spread a thin layer of the cream cheese mixture over one half. Scatter fresh blueberries on top, fold the crepe in half, and then fold it in half again to create a triangle shape. Repeat for each crepe.
Serve warm, garnished with extra blueberries and whipped cream if desired.