*any milk is really fine but whole milk is best!
Melt 3 Tablespoons of butter in the microwave or on the stove. Cool for about 5 minutes before using in the next step. The remaining butter is for the skillet. Combine the cooled melted butter, flour, sugar, salt, milk, water, eggs, and vanilla in a using a wisk or a blender. Blend on medium-high speed for 20–30 seconds until everything is combined. The mixture will be silky-smooth and the consistency of cream. Cover the blender tightly or pour into a medium bowl, cover tightly, and chill in the refrigerator for 15–60 minutes and up to 1 day. (After refrigerating, if the batter looks separated, give it a quick stir before cooking in the next step.)
Cook the crepes: Use the remaining butter for greasing the pan between each crepe. Place an 8-inch skillet over medium heat and generously grease it with some of the reserved butter. If you don’t have a skillet this size, use a larger one, but make sure you keep the crepes thin. Once the skillet is hot, pour 3–4 Tablespoons (closer to 3 is best) of batter into the center of the pan. Tilt/twirl the pan so the batter stretches as far as it will go. The thinner the crepe, the better the texture. Cook for 1–2 minutes, then flip as soon as the bottom is set. Don’t wait too long to flip crepes or else they will taste rubbery. Cook the other side for 30 seconds until set. Transfer the cooked crepe to a large plate and repeat with the remaining batter, making sure to butter the pan between each crepe. If desired, separate each crepe with parchment paper so they do not stick together. If you’re using enough butter in your pan, though, the crepes shouldn’t stick.