Whisk in a large bowl, the flour, cocoa powder, sugar, and salt, until well combined.
Add the eggs and ⅓ cup of the milk to the dry ingredients. Scrape down the sides of the bowl with a rubber spatula, and keep whisking until smooth.
Pour the rest of the milk, a little at a time into the batter, while whisking. Make sure that the batter is smooth after each addition of the milk. Whisk in only 2 tablespoon of the melted butter.
Place the batter in the refrigerator for 20 minutes. Remove from the fridge, and before using, whisk gently to stir around the ingredients before cooking.
Heat up a 9-inch non-stick pan or crêpe pan, on medium-high heat. Once hot, use a silicone brush to very lightly coat the pan with melted butter. Be careful to not add too much butter so that the batter can spread in the pan and not slide.
Hold the pan over the heat, and at a slight angle. Pour ⅓ cup of crêpe batter onto one side of the pan and swirl the pan to evenly distribute the batter to cover the bottom of the pan. If you have a crêpe spreading tool, use that.
Place the pan back on the heat and cook for 30 seconds to a minutes, or until the batter sets on the top and the edges of the crêpe crisp up and release from the edges of the pan.
Use a spatula and your fingers to carefully flip the crêpe over. Cook for another 20-30 seconds or until caramelization spots appear.