01 - Preheat the oven to 400°F and line a baking sheet with parchment paper.
02 - Whisk together flour, sugar, baking powder, baking soda, salt, cinnamon, ginger, cardamom, nutmeg, cloves, and ground tea in a large bowl.
03 - Add cold, cubed butter to the dry ingredients and cut in using a pastry cutter or fingers until mixture resembles coarse crumbs.
04 - Whisk together milk, sour cream, egg, and vanilla extract in a separate bowl.
05 - Pour the wet mixture into the dry ingredients and gently stir with a fork until just combined, avoiding overmixing.
06 - Turn dough onto a lightly floured surface and pat into a 1-inch thick circle approximately 7 inches in diameter.
07 - Cut the dough into 8 even wedges and place them spaced apart on the prepared baking sheet.
08 - Bake for 16 to 18 minutes until golden brown and centers are set.
09 - Transfer scones to a wire rack to cool.
10 - Whisk powdered sugar with chai tea or milk to create a thick but pourable glaze; drizzle over cooled scones.