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 to the dry mixture. Using a pastry cutter or your fingertips, work the butter into the flour until the texture 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 or wooden spoon just until the flour is barely moistened. Do not overmix.
06 - Gently fold in the diced strawberries using a light touch to distribute evenly without crushing the fruit or overworking the dough.
07 - Turn the dough onto a lightly floured work surface. With floured hands, gently pat the dough into a 1-inch-thick round disc, about 7 inches in diameter.
08 - Use a sharp knife or bench scraper to cut the disc into 8 equal wedges. Arrange the wedges on the prepared baking sheet, leaving about 2 inches of space between each.
09 - Brush the tops of each scone with heavy cream using a pastry brush. Sprinkle generously with coarse sugar for a crunchy finish, if desired.
10 - 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.
11 - 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 warm.