Start by placing the cold butter in the freezer for 20-30 minutes—you want it very cold so it creates pockets of steam in the dough for tender, flaky scones. While the butter chills, peel and dice the peaches into 1/2-inch pieces, then toss them with 1 tablespoon of flour to prevent them from sinking during baking. Ensure your sourdough discard is chilled from the refrigerator; cold ingredients are essential for the best scone texture.
While the butter freezes, combine melted and cooled butter, brown sugar, sugar, cinnamon, salt, and 1/3 cup flour in a small bowl to create the streusel topping. Mix until it resembles coarse crumbs, then refrigerate this mixture. In a large bowl, whisk together flour, sugar, baking powder, baking soda, salt, cinnamon, and nutmeg. These dry ingredients form the foundation of your scone dough, and keeping everything cold ensures the best rise and texture.
Remove the frozen butter from the freezer and grate it directly into the bowl of dry ingredients using the large holes of a box grater. This technique is more effective than cutting cubes because it distributes the butter evenly throughout the flour. Using a pastry cutter or fork, gently work the grated butter into the flour mixture until it resembles coarse breadcrumbs with some pea-sized pieces of butter still visible. I find grating cold butter creates a better texture than traditional cutting methods because each strand stays separated and cold.
In a separate bowl, whisk together the egg, chilled sourdough discard, heavy cream, and vanilla until well combined. Create a well in the center of the dry ingredients, pour in the wet mixture, and fold gently until just combined—don't overmix, as this develops gluten and results in tough scones. Fold the flour-coated peaches into the dough gently to distribute them evenly without crushing the fruit.
Turn the dough onto a lightly floured surface and gently shape it into a 1-inch-thick circle without overworking it. Using a sharp knife or bench scraper, cut the circle into 8 equal wedges like a pizza. Place the wedges on a parchment-lined baking sheet and freeze for 1 hour—this crucial step sets the structure and helps them rise properly in the oven. I always freeze scone dough before baking because it prevents them from spreading and keeps the texture light and tender.
Preheat your oven to 400°F. Remove the frozen scones from the freezer and brush the top of each piece lightly with cream. Divide the chilled streusel topping evenly among the scones, pressing it gently onto the cream so it adheres during baking. Bake for 20-25 minutes until the internal temperature reaches 200-205°F on an instant-read thermometer and the tops are golden brown with the topping lightly caramelized.
While the scones bake, whisk together the sifted powdered sugar, milk, fresh lemon juice, and a dash of vanilla in a small bowl until smooth and pourable. Once the scones come out of the oven and have cooled for 2-3 minutes, drizzle the glaze generously over the top of each scone. The warmth of the fresh scones will help the glaze set, creating a beautiful glossy finish that complements the peach cobbler flavors.