Sift together the flour, baking powder, baking soda and salt. Cut the cold butter into the flour until it resembles coarse meal. Stir in the sage. Stir in the buttermilk until the dry ingredients are just moistened.
Lightly flour your hands and work the dough into a square about 7" x 7", 1/2" thick, on a floured surface. Cut the dough into 9 squares, and place on a baking sheet.
Brush the tops with the melted butter and bake until golden brown, 12-14 minute.