Position oven rack to the lowest setting, and remove middle rack. Preheat oven to 42
Lightly coat 6 (8-ounce) souffl dishes with cooking spray.
Sprinkle evenly with 2 tablespoons granulated sugar. Set aside.
Place peaches and 1/3 cup granulated sugar in a food processor; process until smooth.
Combine peach mixture, cornstarch, juice, salt, and egg yolks in a medium saucepan, stirring well with a whisk; bring to a boil. Cook for 1 minute, stirring constantly with a whisk.
Remove from heat; stir in butter. Cool 5 minutes.
Place cream of tartar and egg whites in a large mixing bowl, and beat with a mixer at high speed until soft peaks form.
Add the remaining 1/3 cup granulated sugar, 2 tablespoons at a time, beating until stiff peaks form (do not overbeat). Gently stir 1/4 of egg whites into peach mixture, and gently fold in remaining egg white mixture. Gently spoon the mixture into prepared dishes. Sharply tap dishes 2 or 3 times on counter to level.
Place dishes on a baking sheet, and place baking sheet on the bottom rack of 425 oven. Immediately reduce oven temperature to 350 (do not remove souffls from oven).
Bake for 28 minutes at 350 or until a wooden pick inserted in the side of souffl comes out clean.
