Preheat oven to 375 degrees F (190 degrees C). Lightly grease a 9x13 inch baking pan.
In a large bowl, cream together sugar and shortening. Stir in vanilla. Sift together flour and baking powder. Stir flour into sugar mixture alternately with milk. Mix until smooth. Pour batter into prepared pan and sprinkle with brown sugar and cinnamon.
Bake in preheated oven until a toothpick inserted into center of the pan comes out clean, about 35 to 45 minutes.
