In a saucepan, combine the water and butter over medium heat. Bring to a gentle boil to melt the butter completely.

Once boiling, add flour and salt all at once. Stir vigorously with a wooden spoon until the dough forms a ball and pulls away from the sides of the pan.

Remove the saucepan from heat and let the dough cool for about 5 minutes.

Add the eggs one at a time, mixing well after each addition until the dough is smooth and glossy.

Stir in the vanilla extract until fully combined.

Heat oil in a deep fryer or pot to 350°F (175°C).

Transfer the dough to a pastry bag fitted with a star tip. Pipe 4-inch long strips onto parchment paper, twisting them into a cruller shape.

Carefully place the donuts into the hot oil, frying a few at a time until golden brown, about 2-3 minutes per side.

Remove the donuts with a slotted spoon and let them cool.

In a separate bowl, mix powdered sugar and milk to create the glaze, then dip the warm donuts in the glaze.