In a blender, combine the flour, sugar, salt, milk, eggs, and butter. If you don't have a blender, mix everything together using a whisk.
Puree until the mixture is smooth and bubbles form on top, about 30 seconds.
Heat a 12-inch (30cm) nonstick skillet or pan over medium. Lightly coat with butter. Add 1/3 cup batter and swirl to completely cover bottom of skillet, the crepe should be about 8-inch (20cm) in diameter.
Cook until underside of crepe is golden brown and the edges turn crispy, about 2 to 3 minutes.
Loosen the edge of crepe with a rubber spatula and quickly flip it over. Cook for 1 minute. Slide crepe out of skillet and repeat with remaining batter. (Coat pan with butter as needed.)
Fold the crepes over, serve immediately with powdered sugar, maple syrup, Nutella or chocolate sauce. Add berries of your choice, if you like.