Heat oven to 350. Grease bottom only of 13 X 9 pan. In med. saucepan, melt margarine, stir in flour until smooth. Add brown sugar and 2 eggs and mix well. Cook over med-low heat for 5 minutes, stirring constantly. Remove from heat..stir in vanilla and pecans . Set aside.
In large bowl, combine brownie ingredients and beat 50 strokes with a spoon. Spread in prepared pan. Spoon filling evenly over top. Bake at 350 for 30 to 35 minutes or until set. Do not overbake....Cool completely and cut into 24 bars. This is really great with a scoop of vanilla ice cream but only for those who want a great brownie treat and not someone counting calories!!!!