Blonde Brownies V

Preheat oven to 350 degrees F (175 degrees C). Grease a 9x13 inch pan. In a medium bowl, mix together the margarine, oil, white sugar and brown sugar until well blended. Beat in the eggs one at a time, then stir in the vanilla. Combine the flour, salt and baking powder; stir into the sugar mixture just enough to absorb. Spread the batter evenly into the prepared pan. Bake for 10 minutes in the preheated oven, then cover the pan with foil and return to the oven for an additional 10 to 15 minutes, or until firm. Cool slightly before cutting into bars.