1. Place the sugar, margarine, light-brown sugar, and vanilla extract in the mixer bowl and beat at medium speed until the ingredients are well combined, approximately 5 minutes.
2. Add the egg whites one at a time, beating after each addition.
3. Spoon the flour into a measuring cup, and level it off with a knife.
4. Combine the flour with the cornstarch, baking powder, baking soda, salt, and ground cinnamon in a separate bowl.
5. Add this mixture to the mixer bowl and mix well.
6. Divide the cookie dough into four equal parts. Position each disk between two sheets of plastic wrap and flatten. Freeze the dough for one hour or until it is no longer sticky.
7. Preheat oven to 375 degrees Fahrenheit.
8. On a floured surface, roll out the dough. Use a two-inch cookie cutter to form circles. You can also form balls with a cookie scooper and flatten them on the baking sheet. Bake at 375 degrees Fahrenheit for eight minutes.
