Preheat oven to 375 degrees F. In large bowl, combine flour, baking powder, baking soda, salt and sugar. Cut in butter until mixture resembles coarse meal. Stir in the cinnamon chips.

In another bowl, combine egg yolk, vanilla and buttermilk. Stir into the dry ingredients until just combined. Turn the dough onto a floured surface. Handling it as gently as possible - don't use a rolling pin - pat into a 10-inch circle that is 1/2-inch thick and cut into wedges; or, cut with a 2-inch cookie cutter. Place scones on an ungreased baking sheet. Lightly beat the egg white. Brush tops with the egg white; dust with sugar.

Bake for 16 to 22 minutes, until golden brown. Remove from pan; cool on a wire rack. After 5 minutes, cover loosely with a dishtowel until completely cool. Makes 12 servings.