• Preheat oven to 400ºF (200ºC).  
• Line a baking sheet with parchment paper or grease the bottom.
• Food processor: place 2 ¼ cups all-purpose or pastry flour, 1 tablespoon baking powder, ¼ teaspoon salt, 1 teaspoon ground cinnamon, 4 tablespoons white sugar and 3 tablespoons light brown sugar in the bowl of a food processor fitted with the steel blade. Pulse a few times to mix. Scatter the frozen 6 tablespoons unsalted butter cubes on top, and process on low until the mixture is grainy and the butter the size of peas. Don't overprocess. Transfer the mixture to a large mixing bowl. 
• By hand: add the dry ingredients (2 ¼ cups all-purpose or pastry flour, 1 tablespoon baking powder, ¼ teaspoon salt, 1 teaspoon ground cinnamon, 4 tablespoons white sugar and 3 tablespoons light brown sugar) to a large bowl and combine them well with a spoon or rubber spatula. Scatter the cold 6 tablespoons unsalted butter pieces on top and integrate by hand or with a. The pieces of butter should be the size of peas and beans. It will be irregular. 
• For both methods, drizzle ⅓ cup heavy cream and ½ cup whole milk with ¼ teaspoon vanilla extract (is using) over the flour mixture. Mix with a fork until it barely comes together, but don't mix too much or the scones will be tough and flat.
• Transfer the shaggy dough to a lightly floured surface. Fold it unto itself a few times (I use a dough scraper to help me) and pat it together until you have a circle of dough that holds together. It will still be irregular in places. Don't be tempted to overwork it as you would a pie crust. I don't use a rolling pin, but if you want to, roll it very lightly, you don't want to press it down, simply pat it so it holds together. 
• Make a circle with the dough, about 2 inches high.
• Cut it in half, and then cut each half into 4 triangles. You should have 8 pieces or triangles.
• At this point, they can be frozen, well covered, for up to a month, and baked directly from the freezer. They might take a few more minutes.
• Transfer to the prepared baking sheet, and sprinkle the tops with extra sugar.
• Bake for 15 minutes, turn down the oven temperature to 350°F (180°C), and bake for an additional 10-15 minutes, until golden, dry, and quite firm. If you need to check, with the tip of a fork lift the top of a scone and see if the inside is dry. Depending on the size and height, the bake time might vary, so start checking at the 25-minute mark. 
• Let them cool completely on a wire rack before glazing. 

For the glaze:

• Mix 1 cup powdered sugar, ½ teaspoon ground cinnamon and 2 to 3 tablespoons milk in a medium bowl until smooth and lump-free. It should be like thick honey.
• Drizzle over the cooled scones and let dry before eating.
• I recommend eating them within a few hours of being baked. 
• Store leftovers in an airtight container for a day, maybe two, but the texture is much better the day they're baked.