In a medium-size mixing bowl, blend the first four ingredients together. Then stir in the baking powder and salt followed by the flour and finally the raisins. Pour the mixture into a greased baking pan, either 8"x 8"x 2" for thick bars or 13"x 9"x 2" for thin bars. Bake at 350 degrees until top is nicely browned and a toothpick inserted in the center comes out clean. Cut into bars immediately.