3 cups (375 grams) all-purpose flour¼ cup (50 grams) granulated sugar4 teaspoons (20 grams) baking powder1¼ teaspoons (4 grams) kosher salt¾ cup (170 grams) cold unsalted butter, cubed⅔ cup mix-ins (optional; see Note)1 cup (240 grams) cold heavy whipping cream1 tablespoon (13 grams) vanilla extract1 large egg (50 grams)1 tablespoon (15 grams) water
Line a baking sheet with parchment paper.
In a large bowl, whisk together flour, sugar, baking powder, and salt. Using a pastry blender or 2 forks, cut in cold butter until mixture is crumbly. Stir in mix-ins (if using). Add cold cream and vanilla, stirring with a fork just until mixture starts to come together. Using your hands, knead dough until combined.
Turn out dough onto a lightly floured surface, and roll into a rectangle about 1½ inches thick. Using a bench scraper or bowl scraper, cut dough in thirds; stack dough pieces on top of each other. Repeat rolling, cutting, and stacking procedure one more time. Pat or roll dough to a 1-inch thickness. Using a 2½-inch round cutter, cut dough, rerolling scraps to use all dough. Place 2 inches apart on prepared pan. Freeze until firm, about 15 minutes.
Preheat oven to 375°F (190°C).
In a small bowl, whisk together egg and 1 tablespoon (15 grams) water; brush onto scones.
Bake until golden brown, about 20 minutes. Let cool on pan for 5 minutes. Best served warm. Store in an airtight container for up to 3 days.
Note: Get creative with scone mix-ins. Mini chocolate chips, dried fruit, or chopped nuts make great additions to scones. You can even incorporate a tablespoon of citrus zest or a blend of herbs and a bit of hard or semihard cheese for a savory take. Just be sure that whatever you add is not too large, as big pieces can make it difficult to cut out your scones.