In a blender, combine the all-purpose flour, sugar, salt, milk, eggs, and unsalted butter. If you don't have a blender, you can mix everything using a whisk. Blend until smooth, ensuring no lumps remain and bubbles start to form on top, which should take about 30 seconds.
Heat a 12-inch (30 cm) nonstick skillet over medium heat. Lightly coat the surface with a bit of butter to prevent sticking. Make sure it's hot enough that a drop of water sizzles upon contact.
Pour approximately 1/3 cup of the batter into the skillet, swirling it to completely cover the bottom. Aim for about 8 inches (20 cm) in diameter. You can adjust the amount depending on how thick you want your crepes.
Cook the crepe for 2 to 3 minutes, or until the underside is a golden brown and the edges begin to lift. Keep an eye on it — you want it crispy but not burnt.
Using a rubber spatula, gently loosen the edges of the crepe, then quickly flip it over to cook the other side. This should take about 1 minute, just enough to set the batter.
Slide the crepe out of the skillet and onto a plate. Repeat the process for the remaining batter, adding more butter to the skillet as needed to prevent sticking.
Once you have a stack of crepes, fold them over. You can serve them immediately topped with powdered sugar, maple syrup, Nutella, or chocolate sauce. If desired, add a handful of fresh berries on top for a burst of flavor.
