Step 1 Pulse three-fourths cup of milk, one-half cup of water and the eggs two or three times in a blender until smooth. Add the sugar, cinnamon, salt and flour. Blend the batter until smooth. With the blender running, add melted butter. The batter should be the thickness of heavy cream. If necessary, add up to one-fourth cup more milk to correct the thickness. Strain into a covered bowl, and refrigerate at least 30 minutes.
Step 2 Heat an 8- to 9-inch crepe pan or skillet over medium-high heat until a few drops of water skitter and dance when sprinkled on the surface. Add one-half tablespoon cold butter and swirl to distribute it across the surface. Wipe excess butter from the skillet with a paper towel and return to heat.
Step 3Holding the skillet off the heat with one hand, pour in roughly one-third cup of batter. Swirl quickly across the bottom of the skillet. Pour the excess batter back into the bowl and trim the ragged edge that is left. Return the skillet to the heat and cook until the edges of the crepe begin to brown, about 1 minute. Using a small spatula or table knife, lift the edges of the crepe. Grab the edges with both hands and quickly flip to turn over. Cook the uncooked side just until the crepe slides free in the pan, about 30 seconds. Remove to a plate and cover with wax paper.
Step 4Repeat until all of the batter is used, using the remaining half tablespoon of butter as needed. You should have about 12 crepes. The crepes can be stored, tightly sealed, overnight in the refrigerator.