01 - Preheat the oven to 400°F. Line a baking sheet with parchment paper.
02 - In a large bowl, whisk together the flour, sugar, baking powder, and salt until well blended.
03 - Add the cold butter cubes. Using a pastry cutter or your fingertips, cut the butter into the dry ingredients until the mixture resembles coarse crumbs with some pea-sized pieces remaining.
04 - In a separate bowl, whisk together the heavy cream, sour cream, egg, and vanilla extract until smooth.
05 - Pour the wet mixture into the dry ingredients. Stir gently with a spatula just until the flour is barely moistened. Do not overmix.
06 - Gently fold in the diced strawberries using a light folding motion to avoid crushing the fruit.
07 - Turn the dough onto a lightly floured surface. Pat gently with your hands into a 1-inch-thick round, about 7 inches in diameter.
08 - Use a sharp knife or bench scraper to cut the dough round into 8 equal wedges like a pie.
09 - Transfer the scones to the prepared baking sheet, spacing them about 2 inches apart to allow for spreading.
10 - Brush the tops of each scone with heavy cream using a pastry brush. Sprinkle generously with coarse sugar for a crunchy topping.
11 - Bake for 16 to 18 minutes, or until the scones are golden brown on top and a toothpick inserted into the center comes out clean.
12 - Let the scones cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely for 10 minutes before serving.