Heat oven to 350 degrees. Grease a 9x13 inch pan. Melt margarine in microwave. Mix in brown sugar until blended; cool. Stir in eggs. Mix flour, baking powder and salt, stir in. Blend in vanilla and walnuts. Spread in prepared pan. Bake 25 minutes. Do not over-bake. Cut into bars while a bit warm.
From: Glorious Grub Cookbook By. Joan Stewart
Madagascar Vanilla (purchase at Chefs Catalog) Of all the vanilla's I've used this is my favorite. Once you've tried it you won't go back!