Directions

1. Heat oven to 325 degrees. Butter four 6-ounce glass custard cups; coat with sugar. Line a baking pan with a cloth towel and set aside
2. In an electric mixer with paddle, combine the 2 tablespoons butter, 1/2 cup plus 1 tablespoon sugar, and salt; mix on medium speed until crumbly. Mix in zests and yolks. Mix in flour, then juices and milk.
3. Beat egg whites until stiff. Gently whisk in egg-yolk mixture. Ladle into custard cups; place in prepared baking pan; fill pan halfway with hot water. Bake until puddings have set (tops may crack), about 25 minutes. Cool puddings on a wire rack, 30 minutes. Chill or let stand.

   

4. Meanwhile, combine rhubarb, remaining 3 tablespoons sugar, and 1 tablespoon water in a small skillet; cook over medium-high heat until tender, about 4 minutes. Let cool. Invert puddings onto plates and serve chilled or at room temperature with rhubarb sauce.