Preheat oven to 375F and line cookie sheet with parchment paper.
In large bowl, combine flours, sugar, baking powder, and salt.
Cut in cold butter with pastry cutter until mixture resembles coarse crumbs.
Create a crater in the center of the dry ingredients and gently whisk together egg, milk and vanilla.
Stir into dry ingredients until combined and stir in chocolate chunks (you may have to knead the ingredients a bit with your hands to form a cohesive ball).
Transfer contents to clean, lightly floured surface and form into slightly flattened 8-inch circle and cut into 8 wedges.
Transfer to cookie sheet and brush with milk and sprinkle granulated sugar and oats.