3 1/2 cups margarine, softened
2 1/2 cups white sugar
2 eggs, beaten
1 cup rolled brown sugar
1 teaspoon vanilla extract
2 cups all-purpose flour
2 teaspoons baking powder
Preheat the oven to 375 degrees F (190 degrees C). Grease cookie sheets.
In a large bowl, cream together butter, sugar and eggs until smooth. Mix in the brown sugar and vanilla. Combine the flour, baking powder and baking soda, stir into the creamed mixture until just blended. Drop by rounded spoonfuls onto the prepared cookie sheets.
Bake for 8 to 12 minutes in the preheated oven, until the edges begin to brown. Allow to cool completely. Remove from cookie sheets to wire racks to cool completely.