In a large bowl, whisk together both flours, confectioner’s sugar, baking powder, and salt until well blended. Using a pastry blender (or your fingers), cut in cold butter until mixture resembles coarse sand. Stir in cold buttermilk and shape dough into a ball. Cover with plastic wrap and refrigerate for 30 minutes.
Preheat oven to 350°. Line a rimmed baking sheet with parchment paper.
On a lightly floured surface, roll out dough to a scant ¼-inch thickness. Using a fork, prick dough all over. (This will prevent the cookies from buckling as they bake.) Using a 2½-inch round cutter dipped in flour, cut as many cookies (biscuits) as possible from dough, and place them 1 inch apart on prepared baking sheet.
Bake until tops of cookies are golden brown, approximately 15 minutes. Transfer cookies to a wire rack and let cool completely.
In a microwave-safe bowl, place chocolate. Heat in a microwave oven at 30-second intervals, stirring well between each heating until chocolate melts and is velvety smooth. Either dip the bottom of each cookie into melted chocolate, or dollop a spoonful of melted chocolate onto the bottom of each cookie. Using a knife, smooth chocolate, making sure it covers entire bottoms of cookies. Place cookies chocolate side up on a wire rack. Let chocolate set completely before serving.
Recipe by TeaTime Magazine at https://teatimemagazine.com/ghostly-whispers-and-chocolate-delights-in-this-food-spirits-mystery-by-darci-hannah/