Preheat oven to 350°F (175°C). Greased 9-inch round cake pan also line bottom with parchment paper.
In medium bowl, whisk eggs and 1/4 cup powdered sugar until mixture is light and fluffy.
In another bowl, combine flour and 1 cup powdered sugar.
Gradually add the flour mixture to the egg mixture, stirring until well combined.
In saucepan, melting butter on medium heat. Stir in the milk and water and heat until hot.
Slowly pour the hot liquid into the egg mixture, whisking constantly.
Pour the dough into the prepared cake pan and place the pan in a larger baking dish. Fill the largest dish with enough boiling water to reach half the sides of the cake pan.
Bake for 40 to 45 minutes or until the cake is cooked and a toothpick inserted in the centre comes out clean.
Remove the pan from the water bath and let cool completely. Sprinkle the top with powdered sugar before serving.