Preheat oven to 425°. Line a baking sheet with parchment paper.
In a large bowl, stir together flour, sugar, baking powder, and salt. Using a pastry blender, cut in cold butter until mixture is crumbly. Stir in chocolate and cold buttermilk until a shaggy dough forms.
Turn out dough onto a lightly floured surface. Pat dough into a rectangle, and cut into fourths. Stack each fourth on top of each other, and pat down into a rectangle again. Repeat process 3 more times.
Pat or roll dough to 1-inch thickness. Using a 2½-inch round cutter dipped in flour, cut dough without twisting cutter, rerolling scraps as necessary. Place biscuits 2 inches apart on prepared pan. Freeze until cold, about 10 minutes. Brush with egg.
Bake until golden brown, about 15 minutes. Drizzle with Chocolate Glaze.
Notes
*We used White Lily.
Recipe by Taste of the South at https://tasteofthesouthmagazine.com/chocolate-chip-biscuits-2/