In a large bowl, whisk together the flour, sugar, baking powder, baking soda, salt, cinnamon, and lemon zest until well combined.

Using the large holes of a box grater, grate the frozen butter directly into the flour mixture.

Toss gently with your fingertips to coat the butter shreds with flour. Work quickly so the butter stays cold.

Pop the bowl in the freezer while you prep the wet ingredients (about 2-3 minutes).

In a small bowl, whisk together the buttermilk, egg, and vanilla extract until smooth.

Make a well in the center of the flour mixture.

Pour in the wet ingredients. Add the blueberries.

Using a wooden spoon or spatula, gently mix until the dough just comes together. It will look shaggy and rough. That's exactly what you want.

Turn the dough out onto a lightly floured surface.

Gently shape it into a rough rectangle about 1 inch thick. Fold it in thirds like a letter.

Rotate 90 degrees, pat it out again, and fold in thirds once more. This creates flaky layers without overworking the dough.

Pat the dough into a circle about 8 inches across and 1 inch thick.

Using a bench scraper or sharp knife, cut into 8 equal wedges.

Place the wedges on a parchment-lined baking sheet, spacing them about 2 inches apart.

Refrigerate the shaped scones for at least 15 minutes while your oven preheats. This step is non-negotiable for tall, flaky scones.

Preheat your oven to 400°F (200°C).

Brush the tops of the chilled scones with cream or buttermilk. Sprinkle generously with turbinado sugar.

Bake for 20-24 minutes, until the tops are golden brown and the edges are set.

Let the scones cool on the pan for 5 minutes, then transfer to a wire rack.