Melt 50 g of butter either in the microwave or on the stove. Allow it to cool for a few minutes before adding it to the batter.
In a large bowl, combine the flour and a pinch of salt.
Slowly pour in the milk while whisking constantly to avoid lumps. Next, add the beaten eggs and whisk until smooth. Finally, stir in the cooled melted butter. The batter should be silky and lump-free.
For the best texture, pass the batter through a fine-mesh sieve or chinois to remove any remaining lumps.
Cover the bowl and refrigerate the batter for at least 30–60 minutes.
Heat a lightly buttered non-stick crepe pan (8-inch) over medium heat. Add a small amount of butter to coat the surface evenly, and keep extra butter on hand for greasing between crepes.
Pour 3–4 tablespoons of batter into the pan (use a ladle). Immediately tilt and swirl the pan to spread the batter thinly across the surface.
Cook the crepe for 1–2 minutes, or until the edges start to lift and the underside is golden. Flip the crepe carefully using a spatula, and cook for an additional 30 seconds to 1 minute on the other side.
Transfer the cooked crepes to a plate and repeat the process, ensuring the pan stays lightly buttered for each crepe.