How to Make It
Preheat oven to 375°.
Coat a 1 1/2-quart soufflé dish with cooking spray; sprinkle with 1 tablespoon sugar. Set aside.
Place flour in a small saucepan. Gradually add milk, stirring with a whisk until blended. Add 1/4 cup sugar and rind; stir well. Bring to a boil over medium heat; cook 1 minute or until thickened, stirring constantly. Stir in juice; set aside.
Beat egg whites, cream of tartar, and salt at high speed of a mixer until soft peaks form. Gradually add 2 tablespoons sugar, 1 tablespoon at a time, beating until stiff peaks form. Gently fold one-fourth egg white mixture into orange mixture; gently fold in remaining egg white mixture. Spoon into prepared soufflé dish.
Bake at 375° for 40 minutes or until puffy and set. Sprinkle with powdered sugar. Serve immediately.