Lemon Cheesecake Bars

Lemon Cheesecake Bars
1 box lemon cake mix
1/3 c butter, softened
3 eggs, separated
1 t canola oil
2- 8 oz pkg [fat free] cream cheese
2 c powdered sugar
2 lemons, separated
2 t vanilla

1. Preheat oven to 350*
2. In a medium bowl, blend cake mix, butter, 1 egg, and oil; press into an ungreased 9x13 pan.
3. Use the same medium bowl to beat the cream cheese and gradually blend in powdered sugar.
4. Zest both lemons; set aside one lemon's zest in the fridge and add the other lemon's zest to the cream cheese mixture. Juice both lemons and blend that into the cream cheese mixture.
5. Reserve 1 cup of the cream cheese mixture and refrigerate for later use.
6. Beat remaining 2 eggs, add vanilla, and fold in to cream cheese mixture; spread over cake mixture.
7. Bake for about 25-30 minutes, until set up. Cool completely.
8. Spread the reserved cream cheese mixture on to bars, top with remaining lemon zest, and refrigerate until firm.