Preheat oven to 400°F (200°C) and line a baking sheet with parchment paper.

In a large bowl, whisk together flour, granulated sugar, baking powder, and salt until evenly distributed.

Cut the very cold, cubed butter into the dry ingredients using a pastry blender or your fingertips until coarse crumbs with some pea-sized butter pieces remain, ensuring everything stays cold.

Gently fold in the diced fresh strawberries, tossing lightly to coat them with the flour mixture.

Make a well in the center of the dry ingredients, then pour in the very cold heavy cream or buttermilk and mix gently with a fork until just combined and a shaggy dough forms, avoiding overmixing.

Turn the dough onto a lightly floured surface and gently pat it into a 1-inch thick circle or rectangle, handling it as little as possible.

Cut the dough into wedges or rounds using a sharp, floured knife or cookie cutter, then place them on the prepared baking sheet with space between each.

Freeze the baking sheet with scones for 10-15 minutes or refrigerate for 20-30 minutes to keep the butter cold and prevent spreading.

Brush tops with egg wash and sprinkle with turbinado sugar if desired, then bake for 18-22 minutes until golden brown.

Transfer scones to a wire rack to cool slightly before serving.