1¾ to 2¼ cups whole milk
4 large eggs
½ tsp kosher salt
1½ cups all-purpose flour
6 tbsp unsalted butter, plus additional butter for the pan
Add 1¾ cups of the milk, the eggs, and salt into a blender. Blend for a few seconds to blend everything together. Remove the lid and add the flour. Cover and blend until very smooth. Remove the lid, pour in the melted butter, cover, and blend until combined.
Transfer the batter to a large glass measuring cup with a spout. Allow the batter to rest for at least 5 minutes and up to 24 hours. If resting for more than an hour, store in the fridge. When you’re ready to make the crêpes it should be as thick as heavy cream but not as thick as pancake batter. If it feels too thick, whisk in up to ½ cup of the remaining milk.
Heat an 8-in crêpe pan or nonstick skillet over medium-high heat until it’s hot enough to make a drop of water sizzle upon contact. Using a paper towel, spread about ½ tsp butter around the interior of the pan. The butter should sizzle upon contact but not instantly turn brown. You don’t want the pan to be so hot that the butter burns.
Pour about ¼ cup of the batter into the center of the pan, and at the same time lift the pan from the heat, tilting and turning it in all directions so the batter spreads evenly across the bottom of the pan.
Cook the crêpe until the edges begin to dry and lift from the sides of the pan, and the bottom is nicely browned, usually around 1 minute. When the first side is ready, use a knife, spatula, or your fingers to lift the crêpe and quickly flip it over. Smooth out any folded edges or pleats and then cook until the center is firm and the second side is browned, too, which will occur quickly in as little as 20 seconds more.
Slide the crêpe from the pan onto a large plate. Repeat with the remaining batter, adjusting the heat and wiping the pan with more butter as you cook.