Preheat oven to 450 degrees. Spray a baking sheet with nonstick cooking spray. Set aside.

In a large bowl, sift together flour, baking powder, salt, and sugar. Using a pastry blender, cut shortening into flour until coarsely blended. Make a well in flour mixture and add milk, stirring until just combined.

Turn dough out onto a lightly floured surface. Dust dough with flour and knead lightly 7 or 8 times. Roll dough to a 1-inch thickness. Cut into 2 1/2-inch circles without twisting cutter, rerolling scraps as little as necessary. Place rounds on prepared baking sheet.

Bake for 12 minutes, or until golden brown. Brush tops with melted butter.