Grate the frozen butter directly into the flour mixture using the large holes of a box grater. Gently toss the butter into the flour until evenly distributed and small pieces of butter remain throughout.

In a small bowl, toss the finely chopped strawberries with the cornstarch until evenly coated.

In a separate medium bowl, whisk together the cold heavy cream, egg, and vanilla extract.

Pour the wet ingredients into the dry ingredients and gently stir until the dough just begins to come together. Add the strawberries and fold them in gently. The dough should look shaggy. If it feels excessively wet, add additional flour 1 tablespoon at a time, using only enough to make the dough manageable.

Turn the dough onto a lightly floured work surface. Gently press it into a rectangle about 1 inch thick.

Fold the dough into thirds like a letter. Rotate the dough 90 degrees, gently flatten it into a rectangle again, and repeat the folding process 2–3 more times. Work gently and avoid overmixing.

Pat the dough into a 7–8-inch circle about 1 inch thick. Cut the dough into 8 equal wedges using a sharp knife or bench scraper.

Transfer the scones to a parchment-lined baking sheet and refrigerate for 30 minutes.

Preheat the oven to 400°F.

Brush the chilled scones lightly with heavy cream and sprinkle generously with turbinado sugar.

Bake for 18–22 minutes, or until the tops and edges are golden brown and the centers are cooked through.

Allow the scones to cool on the baking sheet for 5 minutes, then transfer to a wire rack.

If using the lemon glaze, whisk the powdered sugar and lemon juice together until smooth. Drizzle over the cooled scones.