Preheat oven to 450°F (232°C).

Sift together flour and sugar in a bowl.

Cut in shortening using a pastry blender or two knives until the mixture resembles coarse crumbs.

Add buttermilk and stir with a fork just until the dough leaves the sides of the bowl.

Turn the dough out onto a lightly floured board or pastry cloth.

Gently knead the dough until smooth.

Roll out the dough to 1/2-inch thickness.

Cut the dough into rounds using a floured 2 1/2-inch cutter.

Place the biscuit rounds on an ungreased baking sheet.

Bake for 12 to 14 minutes, or until golden brown.

Brush the hot biscuits with melted butter or margarine.

Serve immediately.