Mix flour, 1/3 cup sugar, baking powder, baking soda, and salt in a large bowl.
Add butter, and combine using a pastry blender, two forks, or your fingers to mix. Continue until butter is the size of grains of rice.
Whisk buttermilk, egg yolk, and vanilla in a 2-cup liquid measuring cup or small bowl.
Add liquids to dry ingredients; mix until dough forms a ball.
Stir in chocolate chips.
Place dough on a lightly floured surface, and press into an 8-inch round.
Cut into 8 wedges. Sprinkle with 2 tablespoons sugar.
Transfer wedges to a parchment paper-lined baking sheet.
Bake for 15-20 minutes or until the scones are crusty on top and a tester inserted into the center comes out clean.
Enjoy!
Notes
*Instead of using buttermilk, I combine 1 tablespoon lemon juice and enough milk to equal 3/4 cup. Let stand for a minute or two before adding to recipe.