1/2 cup butter, softened
1 1/2 cups white sugar
2 cups packed light brown sugar
3/4 cup vegetable oil
1 (8 ounce) container frozen whipped topping, thawed
Preheat oven to 250 degrees F (120 degrees C).
In a large bowl, cream together the butter, brown sugar and white sugar. Beat in the oil and whip until smooth. Stir in the brown sugar mixture until completely dissolved. Beat in the frozen whipped topping and spread mixture evenly between the layers of two greased 9 inch pie pans. Place pie on the greased pie pans.
Bake for 1 hour in the preheated oven. Cool completely then frost with chocolate glaze.