In a medium saucepan, combine water, butter, sugar, and salt. Bring to a boil over medium heat. Reduce heat to low, add flour all at once, and stir vigorously until the mixture forms a ball and pulls away from the sides of the pan, about 1 minute.

Remove from heat and let cool for 5 minutes. Beat in eggs and egg white, one at a time, until the dough is smooth and glossy.

Heat vegetable oil in a deep fryer or large pot to 370°F (187°C).

Transfer the dough to a piping bag fitted with a large star tip. Pipe rings of dough onto squares of parchment paper.

Carefully lower the dough rings into the hot oil, parchment paper side up. The parchment paper will detach as they begin to fry; remove it with tongs. Fry the crullers until golden brown, about 2 minutes per side. Transfer to a wire rack to drain.
For the glaze: Whisk together powdered sugar, milk, and vanilla extract until smooth. Dip the top of each cruller into the glaze, then return to the wire rack to let the glaze set.

Serve the crullers fresh for the best taste and texture.

Prep Time: 30 minutes | Cooking Time: 15 minutes | Total Time: 45 minutes
Kcal: 200 kcal per serving | Servings: 12 crullers