In a mixing bowl, whisk together flour, eggs, milk, sugar, and vanilla until smooth. Let the batter rest for 30 minutes.

Heat a non-stick skillet over medium heat and lightly grease it with butter. Pour in about half a cup of batter, swirling to form a thin layer. Cook for about one minute until edges lift slightly; flip and cook for another minute.

In another bowl, mix mascarpone cheese with powdered sugar until creamy. Gently fold in diced strawberries.

Place each crepe on a plate, add filling down the center, roll them up, and serve drizzled with chocolate sauce or dusted with powdered sugar.