Mix flours, sugar, baking powder, baking soda and salt together in a large mixing bowl.
Add the cubes of butter to the flour mixture and using your fingers or a pastry cutter, work the butter into the flour until flour mixture is very coarse.
In a small bowl, whisk sour cream, egg and vanilla until smooth. Use your hands to work the sour cream mixture into flour mixture until the dough starts to come together. Lightly kneed in the chocolate chips. Once the dough completely comes together, turn it onto a clean surface and shape it into a 7-inch flat circle. Cut the circle in half, then cut each half into 3 or 4 triangles, making a total of 6 or 8 scones (I made 6).
Put on a baking sheet, sprinkle with granulated sugar and bake until golden. For 6 scones, this will take 20 – 22 minutes. For 8 scones, it’ll take about 15 to 17 minutes. Cool for 5 minutes before serving.