Preheat oven to 400 degrees F (200 degrees C). Lightly grease two baking sheets.
In a large mixing bowl, combine flour, sugar and baking powder; stir well. Cut in shortening until mixture resembles coarse cornmeal. Add 2 cups buttermilk and mix just to moisten.
Roll out dough to 1 inch thick and cut into biscuits. Place biscuits on prepared baking sheets; brush tops with remaining 1/4 cup buttermilk.
Bake in preheated oven for 15 minutes, or until golden.
