Melt the butter and set aside to cool a little bit.
Place the milk, eggs, salt and sugar in the pitcher of your blender.* Blend for 5 seconds.
Add the flour and blend for 10 seconds. Scrape down the sides of the pitcher and blend another 5 seconds.
Add the melted butter and blend another 5 seconds.
You'll notice in my photos that my gluten-free crepes are not browned. This is intentional. With a high egg content, crepes can get tough and if browned so I choose to keep them pale. Feel free to let yours get a little color if you prefer.
In order to get the right amount of batter into the pan for each crepe, I use a 1/4 c liquid measuring cup which has markings for 4 tablespoons. Pour the right amount of batter in the measuring cup. For an 8" pan use 2 Tbsps batter (2 tbsps is half of a 1/4 cup). For a 10" pan use 3 Tbsps., and for a 12" pan use 1/4 cup.
The heat of the pan is key, so here's how to know if it's the right temperature.
Heat the pan over a medium-high heat for 1-2 minutes. If your pan starts smoking, it's too hot. Take it off the heat for a minute to let it cool down. Heavier pans may require more time. Splash a tiny bit of water on the pan. If it bubbles and evaporates right away it's ready to go. Turn the heat down to medium low.
If your pan is not non-stick wipe on a very light coating of butter.
Once the pan is hot and the batter is measured out, hold the pan in one hand and the measuring cup in the other. Pour the batter into the pan while also swirling the pan to spread the batter out evenly.
Let it cook for 1 minute or until the top is set and the edges start to pull away from the sides of the pan. Use a rubber spatula to gently lift the crepe and flip it supporting it with your fingers.
Cook for 10 more seconds.
Remove to a plate and cover. Continue this process and stack the crepes on the plate keeping covered.