I add the flour, milk, water, eggs, melted butter, sugar, vanilla, and salt into a blender. I blend everything on low speed until the mixture looks completely smooth with no lumps. Then I let the batter rest for about ten minutes so the texture firms up slightly.
I heat a lightly greased non-stick skillet over medium heat until it's warm but not smoking. I pour about a quarter cup of batter into the pan and swirl it quickly to spread it thin. After about a minute, I flip it gently and cook the other side for just twenty seconds more.
Once each crepe is done, I stack them on a plate with a small piece of parchment paper between each one. This keeps them from sticking together while they cool. I let them sit for a few minutes until they're just warm, not hot.
I lay a crepe flat on a plate and place a scoop of softened ice cream just off-center. I work quickly here so the ice cream doesn't melt too fast on the warm crepe. Then I fold the sides over gently to seal in the scoop completely.
I roll the crepe up like a small burrito, tucking the ends in as I go. This keeps the ice cream contained and makes it easy to hold and eat without a mess. I repeat this with the remaining crepes until they're all filled and rolled.
If I have a few extra minutes, I like to pop the rolled crepes into the freezer for about ten minutes before serving. This helps the ice cream firm back up after handling and keeps everything from melting too quickly on the plate.