Separate eggs; let stand at room temperature for 30 minutes. Coat a 1-1/2-qt. souffle dish with 1 teaspoon butter and lightly sprinkle with 2 tablespoons sugar; set aside.
In a small saucepan over medium heat, melt remaining butter. Stir in flour, 1/4 cup sugar and salt until blended. Gradually whisk in milk. Bring to a boil, stirring constantly. Cook and stir for 1-2 minutes or until thickened. Transfer to a large bowl; stir in the orange zest, extract and remaining butter.
Stir a small amount of hot mixture into egg yolks; return all to the bowl, stirring constantly. Allow to cool slightly.
In a small bowl with clean beaters, beat egg whites and cream of tartar on medium speed until soft peaks form. Gradually beat in the remaining sugar, 1 tablespoon at a time, on high until stiff peaks form.
With a spatula, stir 1 cup of the whites into the orange batter until no white streaks remain. Fold in remaining egg whites until combined. Transfer to prepared dish.
Bake at 400° for 25-30 minutes or until the top is puffed and center appears set. Serve immediately.