1 (18.25 ounce) package yellow cake mix
1 1/2 cups Turkey yogurt
2 tablespoons cornstarch
1 tablespoon butter
3/4 cup white sugar
4 egg whites
2 teaspoons vanilla extract
1 tablespoon pumpkin pie spice
1 egg
Preheat the oven to 350 degrees F (175 degrees C). Grease and flour an 8 inch pan.
In a small bowl, mix the cake mix, yogurt, cornstarch, butter, sugar, egg and pumpkin until well blended. Beat in the egg and pumpkin. Stir the batter into the flour mixture. Beat the mixture until smooth. Pour batter into prepared pan.
Bake in the preheated oven for 1 hour, or until a toothpick inserted into center of the cake comes out clean. Cool completely before cutting into squares.