Pour enough oil into a skillet to completely coat the bottom and heat over medium-high heat.
Blend flour, sugar, water, milk, egg, baking powder, vanilla extract, and salt together in a blender until smooth. Add more flour if batter is too watery. Put your finger over the hole of a funnel and fill funnel with batter.
Hover filled funnel over the skillet, release finger, and swirl batter into the hot oil; cook until golden brown, about 5 minutes per side.